Science.gov

Sample records for straightening

  1. Straightening wrinkles

    NASA Astrophysics Data System (ADS)

    Destrade, M.; Ogden, R. W.; Sgura, I.; Vergori, L.

    2014-04-01

    We consider the elastic deformation of a circular cylindrical sector composed of an incompressible isotropic soft solid when it is straightened into a rectangular block. In this process, the circumferential line elements on the original inner face of the sector are stretched while those on the original outer face are contracted. We investigate the geometrical and physical conditions under which the latter line elements can be contracted to the point where a localized incremental instability develops. We provide a robust algorithm to solve the corresponding two-point boundary value problem, which is stiff numerically. We illustrate the results with full incremental displacement fields in the case of Mooney-Rivlin materials and also perform an asymptotic analysis for thin sectors.

  2. Holder for Straightening Bent Tubes

    NASA Technical Reports Server (NTRS)

    Turner, A. R.; Polzien, E. D.

    1985-01-01

    One-piece holder restrains bent metal tube against further bending during straightening operation. Holder consists of handle 16 in. (41 cm) long welded to short, strong tube that fits around tube to be straightened.

  3. Straightening: existence, uniqueness and stability

    PubMed Central

    Destrade, M.; Ogden, R. W.; Sgura, I.; Vergori, L.

    2014-01-01

    One of the least studied universal deformations of incompressible nonlinear elasticity, namely the straightening of a sector of a circular cylinder into a rectangular block, is revisited here and, in particular, issues of existence and stability are addressed. Particular attention is paid to the system of forces required to sustain the large static deformation, including by the application of end couples. The influence of geometric parameters and constitutive models on the appearance of wrinkles on the compressed face of the block is also studied. Different numerical methods for solving the incremental stability problem are compared and it is found that the impedance matrix method, based on the resolution of a matrix Riccati differential equation, is the more precise. PMID:24711723

  4. Straightening: existence, uniqueness and stability.

    PubMed

    Destrade, M; Ogden, R W; Sgura, I; Vergori, L

    2014-04-08

    One of the least studied universal deformations of incompressible nonlinear elasticity, namely the straightening of a sector of a circular cylinder into a rectangular block, is revisited here and, in particular, issues of existence and stability are addressed. Particular attention is paid to the system of forces required to sustain the large static deformation, including by the application of end couples. The influence of geometric parameters and constitutive models on the appearance of wrinkles on the compressed face of the block is also studied. Different numerical methods for solving the incremental stability problem are compared and it is found that the impedance matrix method, based on the resolution of a matrix Riccati differential equation, is the more precise.

  5. Guide for extrusion dies eliminates straightening operation

    NASA Technical Reports Server (NTRS)

    Gyorgak, C. A.; Hoover, R. J.

    1964-01-01

    To prevent distortion of extruded metal, a guidance assembly is aligned with the die. As the metal emerges from the extrusion dies, it passes directly into the receiver and straightening tube system, and the completed extrusion is withdrawn.

  6. Topologically preserving straightening of spinal cord MRI.

    PubMed

    De Leener, Benjamin; Mangeat, Gabriel; Dupont, Sara; Martin, Allan R; Callot, Virginie; Stikov, Nikola; Fehlings, Michael G; Cohen-Adad, Julien

    2017-10-01

    To propose a robust and accurate method for straightening magnetic resonance (MR) images of the spinal cord, based on spinal cord segmentation, that preserves spinal cord topology and that works for any MRI contrast, in a context of spinal cord template-based analysis. The spinal cord curvature was computed using an iterative Non-Uniform Rational B-Spline (NURBS) approximation. Forward and inverse deformation fields for straightening were computed by solving analytically the straightening equations for each image voxel. Computational speed-up was accomplished by solving all voxel equation systems as one single system. Straightening accuracy (mean and maximum distance from straight line), computational time, and robustness to spinal cord length was evaluated using the proposed and the standard straightening method (label-based spline deformation) on 3T T2 - and T1 -weighted images from 57 healthy subjects and 33 patients with spinal cord compression due to degenerative cervical myelopathy (DCM). The proposed algorithm was more accurate, more robust, and faster than the standard method (mean distance = 0.80 vs. 0.83 mm, maximum distance = 1.49 vs. 1.78 mm, time = 71 vs. 174 sec for the healthy population and mean distance = 0.65 vs. 0.68 mm, maximum distance = 1.28 vs. 1.55 mm, time = 32 vs. 60 sec for the DCM population). A novel image straightening method that enables template-based analysis of quantitative spinal cord MRI data is introduced. This algorithm works for any MRI contrast and was validated on healthy and patient populations. The presented method is implemented in the Spinal Cord Toolbox, an open-source software for processing spinal cord MRI data. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1209-1219. © 2017 International Society for Magnetic Resonance in Medicine.

  7. Roller Straightening of Track Pins - A Market Survey

    DTIC Science & Technology

    1989-04-01

    Track pins undergo heat treatment during manufacturing to induce appropriate hardness but warp in the process . Straightening is needed before-further... processing . This is done via chisel straightening (three point bending). Roller straightening should provide improved track pin performance. A market...guidance and knowledge of the roller straightening process . 3 V 4 a 4 TABLE OF CONTENTS Section Page 1.0. INTRODUCTION . ....... . . . . . . . .. . 9 2.0

  8. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Straightening crossed cables. 57.7011 Section... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem... attempts are made to straighten a crossed cable on a reel. ...

  9. Gas turbine rotor straightening -- Case history

    SciTech Connect

    Mazur, Z.; Kubiak, J.; Villela, A.; Orozco, J.

    1999-11-01

    Due to catastrophic damage, the turbine-compressor rotor of a gas turbine has been bent 0.62 mm. The in-situ repair process of rotor straightening is fully described. The repair process included the design of special fixtures for placing the rotor vertically and then hydraulically tensioning the rotor bolts for discs disassembling and run-out check by a special rotary equipment. After the repair process the rotor run-out fell within the design limits. Finally the rotor was put back into service. The approach to the in-house repair of the rotor bend has been successful and can be widely recommended for users of turbomachinery.

  10. 18. VIEW OF ROLLER LEVELER USED TO STRAIGHTEN AND FLATTEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF ROLLER LEVELER USED TO STRAIGHTEN AND FLATTEN METAL SHEETS. (7/2/86) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  11. 6. VIEW OF FIVEFOOT WIND TUNNEL WITH AIR STRAIGHTENER AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF FIVE-FOOT WIND TUNNEL WITH AIR STRAIGHTENER AND OPERATOR STATION IN FOREGROUND (1991). - Wright-Patterson Air Force Base, Area B, Building No. 19, Five-Foot Wind Tunnel, Dayton, Montgomery County, OH

  12. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before...

  13. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before...

  14. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are made...

  15. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are made...

  16. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before...

  17. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are made...

  18. 30 CFR 57.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and Rotary Jet Piercing Drilling-Surface Only § 57.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before...

  19. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are made...

  20. 30 CFR 56.7011 - Straightening crossed cables.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Rotary Jet Piercing Drilling § 56.7011 Straightening crossed cables. The drill stem shall be resting on the bottom of the hole or on the platform with the stem secured to the mast before attempts are...

  1. Optimal intermeshing of multi roller cross roll straightening machine

    NASA Astrophysics Data System (ADS)

    Petruška, Jindřich; Návrat, Tomáš; Šebek, František; Benešovský, Marek

    2016-10-01

    The paper deals with optimal setting of intermeshing parameters in multi roller cross roll straightening machine. The procedure is based on a fast algorithm of the straightening process simulation, which leads to an efficient analysis of the process for many combinations of intermeshing parameters, selected at random. Multi-objective optimization is then realized over the obtained response variables. Presented example shows the potential of the suggested solution strategy.

  2. Electric hair straightener burns an epidemiological and thermodynamic study.

    PubMed

    Wilson Jones, N; Wong, P; Potokar, T

    2008-06-01

    Hair straighteners are a popular beauty product in the UK. An alarming rise in admissions to the Welsh Centre for Burns and Plastic Surgery, for burns caused by hair straighteners has led to this study. A thermodynamic study was also performed to look at temperature range and cooling profiles of these devices. Thirty-one cases were identified over a 32-month period, January 2003 to August 2006. Ninety-three percent (29 cases) were children with an average age of 4 years. The majority of burns were partial thickness to hands and feet, but 23% (seven cases) required admission and 10% (three cases) required surgical intervention. The hair straighteners reached a maximum temperature of 145 degrees C within 2min of activation and took up to 7min to cool below a temperature that would burn adult skin with a 1s contact. Children and crawling babies are at particular risk from preventable burns from hair straighteners. The frequency of burns from hair straighteners is rising and even small burns to the hand can have serious sequelae and need to be treated in specialist centres. Health promotion and discussion with the industry is required to stop this new and increasing problem.

  3. Taylorwilson four roll straightener of the no. 1 seamless line ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Taylor-wilson four roll straightener of the no. 1 seamless line in bay 12 of the main pipe mill building. - U.S. Steel National Tube Works, Main Pipe Mill Building, Along Monongahela River, McKeesport, Allegheny County, PA

  4. Flow Straightener for a Rotating-Drum Liquid Separator

    NASA Technical Reports Server (NTRS)

    O'Coin, James R.; Converse, David G.; Rethke, Donald W.

    2004-01-01

    A flow straightener has been incorporated into a rotary liquid separator that originally comprised an inlet tube, a shroud plate, an impeller, an inner drum, an outer drum, a housing, a pitot tube, and a hollow shaft motor. As a consequence of the original geometry of the impeller, shroud, inner drum, and hollow shaft, swirl was created in the airflow inside the hollow shaft during operation. The swirl speed was large enough to cause a significant pressure drop. The flow straightener consists of vanes on the back side of the shroud plate. These vanes compartmentalize the inside of the inner drum in such a way as to break up the flow path and thereby stop the air from swirling; as a result, the air enters the hollow shaft with a predominantly axial velocity instead of a swirl. Tests of the rotary liquid separator at an airflow rate of 10 cu ft/min (0.0047 cu m/s) revealed that the dynamic pressure drop was 8 in. of water (approx.=2 kPa) in the absence of the flow straightener and was reduced to 1 in. of water (approx.=0.25 kPa) in the presence of the flow straightener.

  5. Postural orientation in microgravity depends on straightening up movement performed

    NASA Astrophysics Data System (ADS)

    Vaugoyeau, Marianne; Assaiante, Christine

    2009-08-01

    Whether the vertical body orientation depends on the initial posture and/or the type of straightening up movement is the main question raised in this paper. Another objective was to specify the compensatory role of visual input while adopting an erected posture during microgravity. The final body orientation was analysed in microgravity during parabolic flights. After either (1) straightening up movement from a crouching or (2) a sitting posture, with and without vision. The main results are the following: (1) a vertical erected final posture is correctly achieved after sit to stand movement, whereas all subjects were tilted forward after straightening up from a crouching posture and (2) vision may contribute to correct final posture. These results suggest the existence of a re-weighting of the remaining sensory information, visual information, contact cutaneous cues and proprioceptive information under microgravity condition. We can put forward the alternative hypothesis that the control of body orientation under microgravity condition may also be achieved on the basis of a postural body scheme, that seems to be dependant on the type of movement and/ or the initial position of the whole body.

  6. Hyperplasticity effect under magnetic pulse straightening of dual phase steel

    NASA Astrophysics Data System (ADS)

    Falaleev, AP; Meshkov, VV; Shymchenko, A.

    2016-10-01

    An investigation of the behaviour of dual phase steel parts during straightening operations, by means of magnetic pulse treatment, is presented. The mechanical analysis of magnetic-pulse treatment for the straightening of thin-walled sheet metal parts produced from dual phase steel was performed, taking into account the effect of hyperplasticity under the influence of the magnetic field. Taking account of the causes of the hyperplasticity and thus the increase of material plasticity, it has been shown that the magnetic impulse gravity can be adjusted by controlling the operation modes. The dependence of the generated magnetic impulse gravity force on the electrical current strength inducted in this part was explored and used for analysis of the magnetic pulse straightening of dual phase steel part. Experimental results were obtained for thin-walled sheet metal part produced from dual phase steel DP 780. The results are used to demonstrate the material deformation under the influence of magnetic impulse gravity force considering the increase of material plasticity. The dependence of relative material deformation on the generated magnetic impulse gravity as well as on the current strength induced in this material was obtained and analyzed

  7. Vision system for gauging and automatic straightening of steel bars

    NASA Astrophysics Data System (ADS)

    Sidla, Oliver; Wilding, Ernst; Niel, Albert; Barg, Herbert

    2001-02-01

    A machine vision application for the fully automatic straightening of steel bars is presented. The bars with lengths of up to 6000 mm are quite bent on exit of the rolling mill and need to be straightened prior to delivery to a customer. The shape of the steel bar is extracted and measured by two video resolution cameras which are calibrated in position and viewing angle relative to a coordinate system located in the center of the roller table. Its contour is tracked and located with a dynamic programming method utilizing several constraints to make the algorithm as robust as possible. 3D camera calibration allows the transformation of image coordinates to real-world coordinates. After smoothing and spline fitting the curvature of the bar is computed. A deformation model of the effect of force applied to the steel allows the system to generate press commands which state where and with what specific pressure the bar has to be processed. The model can be used to predict the straightening of the bar over some consecutive pressing events helping to optimize the operation. The process of measurement and pressing is repeated until the straightness of the bar reaches a predefined limit.

  8. Assessment and Treatment of Excessive Straightening and Destructive Behavior in an Adolescent Diagnosed with Autism

    ERIC Educational Resources Information Center

    Kuhn, David E.; Hardesty, Samantha L.; Sweeney, Nicole M.

    2009-01-01

    Repetitive behaviors such as excessive straightening are commonly observed among individuals with autism. Attempts to prevent these behaviors may increase the likelihood of other problem behaviors. The present study was designed to assess and treat the excessive straightening and associated destructive behaviors of a 16-year-old boy who had been…

  9. Restoring the sinuosity of artificially straightened stream channels

    SciTech Connect

    Brookes, A. )

    1987-01-01

    Restoration of Danish stream channels is encouraged by the Watercourse Act of 1982 and has been undertaken partly because of the adverse physical and biological effects caused by artificial straightening. A new technique for restoring morphologic and hydrologic diversity to stream channels has been developed, exemplifying the concept of working with nature rather than against it. This relies on re-creating the former sinuosity, cross-sectional dimensions, slope and substrate of a stream channel. Natural fluvial features are restored to a channel, and because slope is decreased stability is probable. In turn, this could be beneficial to the flora and fauna of a watercourse and to aesthetic qualities. The technique was applied successfully to a small stream in southern Jutland, Denmark, in 1984/5. Additional methods of bank and bed protection were required to limit subsequent minor adjustments along the new course. Further applications of the technique need to be treated individually because of varying local hydrologic and sedimentologic conditions. On-site supervision during construction and planned maintenance are vital components of restoration.

  10. Autonomic straightening after gravitropic curvature of cress roots

    NASA Technical Reports Server (NTRS)

    Stankovic, B.; Volkmann, D.; Sack, F. D.

    1998-01-01

    Few studies have documented the response of gravitropically curved organs to a withdrawal of a constant gravitational stimulus. The effects of stimulus withdrawal on gravitropic curvature were studied by following individual roots of cress (Lepidium sativum L.) through reorientation and clinostat rotation. Roots turned to the horizontal curved down 62 degrees and 88 degrees after 1 and 5 h, respectively. Subsequent rotation on a clinostat for 6 h resulted in root straightening through a loss of gravitropic curvature in older regions and through new growth becoming aligned closer to the prestimulus vertical. However, these roots did not return completely to the prestimulus vertical, indicating the retention of some gravitropic response. Clinostat rotation shifted the mean root angle -36 degrees closer to the prestimulus vertical, regardless of the duration of prior horizontal stimulation. Control roots (no horizontal stimulation) were slanted at various angles after clinostat rotation. These findings indicate that gravitropic curvature is not necessarily permanent, and that the root retains some commitment to its equilibrium orientation prior to gravitropic stimulation.

  11. Autonomic Straightening after Gravitropic Curvature of Cress Roots1

    PubMed Central

    Stanković, Bratislav; Volkmann, Dieter; David Sack, Fred

    1998-01-01

    Few studies have documented the response of gravitropically curved organs to a withdrawal of a constant gravitational stimulus. The effects of stimulus withdrawal on gravitropic curvature were studied by following individual roots of cress (Lepidium sativum L.) through reorientation and clinostat rotation. Roots turned to the horizontal curved down 62° and 88° after 1 and 5 h, respectively. Subsequent rotation on a clinostat for 6 h resulted in root straightening through a loss of gravitropic curvature in older regions and through new growth becoming aligned closer to the prestimulus vertical. However, these roots did not return completely to the prestimulus vertical, indicating the retention of some gravitropic response. Clinostat rotation shifted the mean root angle −36° closer to the prestimulus vertical, regardless of the duration of prior horizontal stimulation. Control roots (no horizontal stimulation) were slanted at various angles after clinostat rotation. These findings indicate that gravitropic curvature is not necessarily permanent, and that the root retains some commitment to its equilibrium orientation prior to gravitropic stimulation. PMID:9662531

  12. Straightening tubular flow for side-by-side visualization.

    PubMed

    Angelelli, Paolo; Hauser, Helwig

    2011-12-01

    Flows through tubular structures are common in many fields, including blood flow in medicine and tubular fluid flows in engineering. The analysis of such flows is often done with a strong reference to the main flow direction along the tubular boundary. In this paper we present an approach for straightening the visualization of tubular flow. By aligning the main reference direction of the flow, i.e., the center line of the bounding tubular structure, with one axis of the screen, we are able to natively juxtapose (1.) different visualizations of the same flow, either utilizing different flow visualization techniques, or by varying parameters of a chosen approach such as the choice of seeding locations for integration-based flow visualization, (2.) the different time steps of a time-dependent flow, (3.) different projections around the center line , and (4.) quantitative flow visualizations in immediate spatial relation to the more qualitative classical flow visualization. We describe how to utilize this approach for an informative interactive visual analysis. We demonstrate the potential of our approach by visualizing two datasets from two different fields: an arterial blood flow measurement and a tubular gas flow simulation from the automotive industry.

  13. Comparison of Nozzle and Flow Straighteners for Tank Waste Sluicing Applications Letter Report

    SciTech Connect

    Mullen, O Dennis; Jackson, David R.

    2000-09-29

    Nozzles and flow straighteners were compared to assess the relative quality of the water streams for sluicing waste from underground storage tankes. The criteria for comparison were 1) the impact force produced by the streams over a range of distance from the nozzle impinging on target plates, and 2) the coherence of the streams as manifest by the variation of force on targets of two different sizes. It was determined that 1) the standard Hanford flow straightener is measurable less effective than a commercial firefighting flow straightener at producing a coherent stream when used with the standard Hanford nozzle, and 2) a lighter and more compact firefighting deluge nozzle will deliver a stream of equal quality to that from the Hanford nozzle when either nozzle is used with the commercial flow straightener.

  14. Tensile Straightening of Superfine Wire and Residual Stress Measurement Using Focused Ion Beam

    NASA Astrophysics Data System (ADS)

    Yamashita, Tsutomu; Yoshida, Kazunari

    The general method of reducing curving or bending for midsize wires or sheets is straightening using rollers and/or levelers. For superfine wires, similarly, high straightness is needed. However, it is very difficult to deal with superfine wires due to their fineness and low tensile strength. In our study, warm tensile straightening processes for superfine gold wire, which is widely used as bonding material between leads and IC chips in semiconductors, were examined. Furthermore, finite element analyses of drawing and tensile straightening of superfine wires were carried out. The correlation between straightness and axial residual stress, which was calculated using the curve width when half of the wire was removed by sputtering with a focused ion beam (FIB), was studied. As a result of our studies, the improvement of straightness by tensile straightening of superfine gold wire was demonstrated, and the relationship between axial residual stress and straightness of wires was clarified.

  15. Protein loss in human hair from combination straightening and coloring treatments.

    PubMed

    França-Stefoni, Simone Aparecida; Dario, Michelli Ferrera; Sá-Dias, Tânia Cristina; Bedin, Valcinir; de Almeida, Adriano José; Baby, André Rolim; Velasco, Maria Valéria R

    2015-09-01

    Hair chemical treatments, such as dyeing and straightening products, are known to cause damage that can be assessed by protein loss. The aim of this study was to evaluate the hair protein loss caused by combined chemical treatments (dye and relaxer) using the validated bicinchoninic acid (BCA) method. Three kinds of straighteners, based on ammonium thioglycolate, guanidine hydroxide and sodium hydroxide, were evaluated and the least harmful combination indicated. Caucasian virgin dark brown hair tresses were treated with developed natural brown color oxidative hair dyeing and/or straightening commercial products based on ammonium thioglycolate, sodium hydroxide, or guanidine hydroxide. Protein loss quantification was assessed by the validated BCA method which has several advantages for quantifying protein loss in chemically treated hair. When both treatments (straightening and dyeing) were combined, a higher negative effect was observed, particularly for dyed hair treated with sodium hydroxide. In this case, a 356% increase in protein loss relative to virgin hair was observed and 208% in relation to only dyed hair. The combination of dying and relaxers based on ammonium thioglycolate or guanidine hydroxide caused a small increase in protein loss, suggesting that these straightening products could be the best alternatives for individuals wishing to combine both treatments. These results indicated that when application of both types of products is desired, ammonium thioglycolate or guanidine hydroxide should be chosen for the straightening process. © 2015 Wiley Periodicals, Inc.

  16. Design Optimization of Roller Straightening Process for Steel Cord using Response Surface Methodology

    SciTech Connect

    Lee, Jong-Sup; Huh, Hoon; Bae, Jong-Gu; Lee, Jun-Wu; Kim, Deuk-Tae

    2007-05-17

    A roller straightening process is a metal forming technique to improve the geometric quality of products such as straightness and flatness. The geometrical quality can be enhanced by eliminating unnecessary deformations produced during upstream manufacturing processes and minimizing any detrimental internal stress during the roller straightening process. The quality of steel cords can be achieved by the roller straightening depends the process parameters. Such process parameters are the roll intermesh, the roll pitch, the diameter of rolls, the number of rolls and the applied tension. This paper is concerned with the design optimization of the roller straightening process for steel cords with the aid of elasto-plastic finite element analysis. Effects of the process parameters on the straightness of the steel cord are investigated by the finite element analysis. Based on the analysis results, the optimization of the roller straightening process is performed by the response surface method. The roller straightening process using optimum design parameters is carried out in order to confirm the quality of the final products.

  17. Design Optimization of Roller Straightening Process for Steel Cord using Response Surface Methodology

    NASA Astrophysics Data System (ADS)

    Lee, Jong-Sup; Huh, Hoon; Bae, Jong-Gu; Lee, Jun-Wu; Kim, Deuk-Tae

    2007-05-01

    A roller straightening process is a metal forming technique to improve the geometric quality of products such as straightness and flatness. The geometrical quality can be enhanced by eliminating unnecessary deformations produced during upstream manufacturing processes and minimizing any detrimental internal stress during the roller straightening process. The quality of steel cords can be achieved by the roller straightening depends the process parameters. Such process parameters are the roll intermesh, the roll pitch, the diameter of rolls, the number of rolls and the applied tension. This paper is concerned with the design optimization of the roller straightening process for steel cords with the aid of elasto-plastic finite element analysis. Effects of the process parameters on the straightness of the steel cord are investigated by the finite element analysis. Based on the analysis results, the optimization of the roller straightening process is performed by the response surface method. The roller straightening process using optimum design parameters is carried out in order to confirm the quality of the final products.

  18. Mechanical characterization of curly hair: Influence of the use of nonconventional hair straightening treatments.

    PubMed

    Leite, M G A; Maia Campos, P M B G

    2017-11-01

    Hair straighteners are very popular around the world, although they can cause great damage to the hair. Thus, the characterization of the mechanical properties of curly hair using advanced techniques is very important to clarify how hair straighteners act on hair fibers and to contribute to the development of effective products. On this basis, we chose two nonconventional hair straighteners (formaldehyde and glyoxylic acid) to investigate how hair straightening treatments affect the mechanical properties of curly hair. The mechanical properties of curly hair were evaluated using a tensile test, differential scanning calorimetry (DSC) measurements, scanning electronic microscopy (SEM), a torsion modulus, dynamic vapor sorption (DVS), and Fourier transform infrared spectroscopy (FTIR) analysis. The techniques used effectively helped the understanding of the influence of nonconventional hair straighteners on hair properties. For the break stress and the break extension tests, formaldehyde showed a marked decrease in these parameters, with great hair damage. Glyoxylic acid had a slight effect compared to formaldehyde treatment. Both treatments showed an increase in shear modulus, a decrease in water sorption and damage to the hair surface. A combination of the techniques used in this study permitted a better understanding of nonconventional hair straightener treatments and also supported the choice of the better treatment, considering a good relationship between efficacy and safety. Thus, it is very important to determine the properties of hair for the development of cosmetics used to improve the beauty of curly hair. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. 'Straightening-reinforcing' technique for congenital curvature and Peyronie's disease.

    PubMed

    Mantovani, Franco; Patelli, Emilio; Castelnuovo, Chiara; Nicola, Massimiliano

    2005-01-01

    We report an initial randomised study on surgical techniques with subsequent intensive application of our procedure. We modified Ebbehoj-Metz technique by a 'straightening-reinforcing' (S-R) double stitch: the first performs the plication, the second tightens it, thus preventing tension during erection. This is different to the simple Ebbehoj-Metz stitch that only provides plication but, as it does not provide reinforcement, does not prevent recurrence. From 1995 to 2000 78 plications were performed: 60 for congenital curvatures (age range 18-32 years) and 18 for Peyronie's disease (PD; age range 36-58 years). During the first 3 years, i.e. between 1995 and 1998, patients were randomised to S-R plication (20 congenital and 5 PD) and Nesbit procedure (20 congenital and 5 PD), for a total number of 50 patients (40 congenital and 10 PD). The last 28 patients, operated between 1998 and 2000, were assigned exclusively to S-R plication. We delayed study publication in favour of an adequate follow-up. No patient reported a decrease in erectile function and all reported easy vaginal penetration within 3 months. In 60% of the patients undergoing the Nesbit technique, restoration of a fully satisfactory coital activity was delayed because of pain during erection; 35% of all patients had some problems with the coronal suture which disappeared 1 month after the operation, and 15% reported decreased sensibility of the glans. Recurrence rate was not significant for all patients of all groups, even if 3 PD patients of the S-R plication group and 1 PD patient of the Nesbit group received no benefit from the operation. S-R plication is not better than the Nesbit procedure. However, for low degrees of penile bending, both congenital and acquired, we do not think it strictly necessary to perform the more invasive Nesbit operation (requiring opening of Buck's fascia, detachment of the neurovascular dorsal bundle or urethra and albuginea excision). Modified plication may be a minimally

  20. The projective geometric theory of systems of second-order differential equations: straightening and symmetry theorems

    SciTech Connect

    Aminova, Asya V; Aminov, Nail' A-M

    2010-06-29

    In the framework of the projective geometric theory of systems of differential equations, which is being developed by the authors, conditions which ensure that a family of graphs of solutions of a system of m second-order ordinary differential equations y-vector-ddot=f-vector(t,y-vector,y-vector-dot) with m unknown functions y{sup 1}(t),...,y{sup m}(t) can be straightened (that is, transformed into a family of straight lines) by means of a local diffeomorphism of the variables of the system which takes it to the form z-vector''=0 (straightens the system) are investigated. It is shown that the system to be straightened must be cubic with respect to the derivatives of the unknown functions. Necessary and sufficient conditions for straightening the system are found, which have the form of differential equations for the coefficients of the system or are stated in terms of symmetries of the system. For m=1 the system consists of a single equation y-ddot=f-vector(t,y,y-dot), and the tests obtained reduce to the conditions for straightening this equations which were derived by Lie in 1883. Bibliography: 34 titles.

  1. Method for producing ultrafine-grained materials using repetitive corrugation and straightening

    DOEpatents

    Zhu, Yuntian T.; Lowe, Terry C.; Jiang, Honggang; Huang, Jianyu

    2001-01-01

    A method of refining the grain structure and improving the hardness and strength properties of a metal or metal alloy workpiece is disclosed. The workpiece is subjected to forces that corrugate and then straighten the workpiece. These steps are repeated until an ultrafine-grained product having improved hardness and strength is produced.

  2. HEU Holdup Measurements in the 321-M Draw Bench, Straightener, and Fluoroscope Components

    SciTech Connect

    Dewberry, R.A.

    2001-07-10

    The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facilities Disposition Division (FDD) to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. This report covers holdup measurements of uranium residue on the draw bench, straightener, and the fluoroscope components of the 321-M facility.

  3. 155 burns caused by hair straighteners in children: a single centre's experience over 5 years.

    PubMed

    Sarginson, Julia H; Estela, Catalina; Pomeroy, Shirin

    2014-06-01

    Hair straighteners have become a popular and common household appliance. The incidence of burns from these devices is rising, and is of particular concern given that the main casualties are infants. We present the largest case series in the literature of paediatric burns from hair straightening devices. Retrospective data collection of all burns by hair straightening devices presenting to our unit between 2007 and 2011. Details on demographics, time and mechanism of injury, size and depth of injury and treatment received were recorded. There were 155 cases in the five-year period. The mean age was 19 months. The majority of the burns were caused by a 'touch/grab' (49%) or 'stepped-into' (14%) mechanism. The area most frequently burnt was the hand with 60% of the injuries. 8 out of the 155 required excision and grafting. Hair straightening devices can reach temperatures of over 220°C and can cause significant full thickness injuries. Our study shows that infants and toddlers are at most risk. These are preventable burns that warrant our attention, and we would advocate the use of heat-resistant pouches and closure clips on the devices to help minimise the risk of injury. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  4. Formaldehyde in hair straightening products: rapid ¹H NMR determination and risk assessment.

    PubMed

    Monakhova, Yulia B; Kuballa, Thomas; Mildau, Gerd; Kratz, Evamaria; Keck-Wilhelm, Andrea; Tschiersch, Christopher; Lachenmeier, Dirk W

    2013-04-01

    Despite official regulations, the illegal use of formaldehyde-containing or releasing hair straightening products has become a popular practice in Europe and high contents of formaldehyde in such products have been reported. In this study, a methodology utilizing (1)H NMR spectroscopy has been developed to measure the concentration of formaldehyde in hair straightening products. For sample preparation, a dilution and alkaline hydrolysis is required. The total formaldehyde content can then be quantified by a distinct peak of the CH2 group of the methanediol molecule in the δ4.84-4.82 ppm range. The developed methodology was applied for the analysis of 10 hair straightening products. Seven of these products contained detectable amounts of formaldehyde that were higher than the maximum allowed concentration of 0.2%. The formaldehyde content of these products was found to be in the range 0.42-5.83% with an average concentration of 1.46%. The accuracy and reliability of the NMR results were confirmed by the EU reference photometric method. The air formaldehyde concentrations after application of hair straightening products were estimated in ranges 20-423 ppm and 1-18 ppm (for 1 and 24 m(3) salon volume). A probabilistic exposure estimation using Monte Carlo simulation found the average formaldehyde concentration to be 6 ppm (standard deviation 15 ppm). All exposure scenarios considerably exceeded the safe level of 0.1 ppm. Our findings confirmed that the risk of cosmetic formulations with formaldehyde above 0.2% is not negligible, as these products may facilitate considerable exposure of formaldehyde for consumers especially for salon workers. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  5. Influence of thermal hair straightening on cannabis and cocaine content in hair.

    PubMed

    Ettlinger, Jana; Yegles, Michel

    2016-08-01

    It has been shown that cosmetic treatment like bleaching and perming may lead to an important decrease of drugs of abuse content in hair. Currently, hair straightening has become a regular hair treatment especially for women. The aim of this preliminary study was to investigate the effect of in vitro treatment of hair with heat straightener on cannabis and cocaine concentrations in hair. 17 positive cannabis and 7 positive cocaine hair samples were treated in vitro with a hair straightener. During this treatment hair was put sequentially 30 times in contact with heated iron plates at 200°C during 2s corresponding to a total time of contact of 1min. THC and Cannabinol (CBN) were analysed in cannabis positive hair and cocaine, benzoylecgonin (BZE) and cocaethylene were analysed in cocaine positive hair. Analyses were performed with routine methods using GC/MS in electron impact mode. Regarding cannabis results a decrease of THC concentrations was found in 11 of 17 hair samples after thermal treatment, whereas in 6 cases an increase was shown. In all the hair samples CBN concentrations was explicitly higher after the in vitro treatment. Regarding cocaine results cocaine and cocaethylene concentrations decreased after treatment in all seven hair samples; in contrast, higher concentrations of BZE were determined. The strong increase of CBN and BZE content in hair after thermal treatments may be due to the fact that THC is converted by heat into CBN and cocaine into BZE, thus changing the respective ratios of the analysed substances. In conclusion, thermal straightening should be considered as other cosmetic hair treatments for a correct interpretation of hair results.

  6. Influence of thermal hair straightening on ethyl glucuronide content in hair.

    PubMed

    Ettlinger, Jana; Kirchen, Luc; Yegles, Michel

    2014-06-01

    Hair analysis of ethyl glucuronide (EtG) has become a valuable marker for the detection of moderate and chronic alcohol consumption. It has been shown that bleaching and perming may decrease EtG content in hair. So far, no studies exist about the influence of thermal hair straightening on EtG content in hair. Forty-one positive EtG hair samples were treated in vitro with a hair straightener at 200°C. Duration of treatment of 1 min was chosen for this study. After washing, pulverization, incubation in ultrasonic bath, solid-phase extraction, and derivatization with heptafluorobutyric anhydride, EtG was determined by gas chromatography-mass spectrometry - negative ion chemical ionization (GC-MS-NICI). The EtG contents in straightened hair strands were then compared with those in the corresponding untreated strands. In 20 of 41 hair samples, a decrease of EtG content was found ranging from 0.7% to 79.3% (average 20%) whereas in 21 cases an increase was shown ranging from 2.0% to 50.9% (average 15%). The variation of the results seems to depend on hair colour. The decrease may be explained by thermic in vitro destruction of EtG. The increase may be explained by denaturation of the hair matrix by thermal treatment possibly causing a better extraction of EtG during incubation in ultrasonic bath. This in vitro study indicates that thermal hair straightening has an impact on the EtG content in hair. This has to be considered for a correct interpretation of EtG results in hair. However, these results should be confirmed by in vivo studies.

  7. Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion.

    PubMed

    Dias, Tania Cristina de Sá; Baby, André Rolim; Kaneko, Telma Mary; Velasco, Maria Valéria Robles

    2008-06-01

    Straightening is a chemical process by which excessively curly hair is straightened in an irreversible way. Generally, products are formulated as emulsions with high pH value (9.0-12.0), which, after applied on hair, cause considerable damage, making it dry and fragile. This research work evaluated the protective effect of lauryl PEG/PPG-18/18 methicone, cyclopentasiloxane (and) PEG-12 dimethicone cross-polymer, jojoba oil, and aqua (and) cystine bis-PG propyl silanetriol, as conditioning agents, on Afro-ethnic hair locks treated with thioglycolate-based straightening emulsions by protein loss, combability, and traction to rupture. Standard Afro-ethnic hair locks were prepared following a protocol for straightening emulsion application. Considering the assays performed, the addition of conditioning agents to the straightening emulsion with ammonium thioglycolate benefited the hair fiber, thus diminishing protein loss, protecting the hair thread, and improving resistance to breakage. Jojoba oil and lauryl PEG/PPG-18/18 methicone were the conditioning agents that presented the best results. Straightening emulsions with ammonium thioglycolate containing aqua (and) cystine bis-PG propyl silanetriol and cyclopentasiloxane (and) PEG-12 dimethicone cross-polymer were the ones that provided higher breakage resistance of the thread.

  8. Effect of Patency File on Transportation and Curve Straightening in Canal Preparation with ProTaper System.

    PubMed

    Hasheminia, Seyed Mohsen; Farhadi, Nastaran; Shokraneh, Ali

    2013-01-01

    The aim of this ex vivo study was to evaluate the effect of using a patency file on apical transportation and curve straightening during canal instrumentation with the ProTaper rotary system. Seventy permanent mandibular first molars with mesiobuccal canals, measuring 18-23 mm in length and with a 25-40° curvature (according to the Schneider method), were selected. The working lengths were determined and the teeth were mounted and divided into two experimental groups: (A) prepared by the ProTaper system without using a patency file (n = 35) and (B) prepared by the ProTaper system using a patency file (n = 35). Radiographs taken before and after the preparation were imported into Photoshop software and the apical transportation, and curve straightening were measured. Data were analyzed using independent t-test. Partial correlation analysis was performed to evaluate the relationship between the initial curvature, transportation, and curve straightening (α = 0.05). Using a patency file during canal preparation significantly decreased both apical transportation and curve straightening (P < 0.001). There were significant relationships between the angle of curvature, transportation and curve straightening in pairs (P < 0.001). Apical patency is recommended during root canal preparation with the ProTaper rotary system.

  9. Influence of chemical straightening on the stability of drugs of abuse in hair.

    PubMed

    Pritchett, Jeanita S; Phinney, Karen W

    2015-01-01

    Chemical straightening, also known as a relaxer, is ubiquitously used among African American women to obtain straighter hair compared with their natural tresses. This study focused on the stability of drugs of abuse in hair after a single application of the relaxer. Commercially available 'Lye' or 'No-Lye' chemical straightening products (Silk Elements™) were applied in vitro to drug-fortified hair (standard reference materials (SRM) 2379 and 2380) and hairs clipped from established drug users. Target analytes (cocaine (COC), benzoylecgonine (BZE), cocaethylene (CE), phencyclidine and tetrahydrocannabinol) were isolated using solid-phase extraction and then analyzed with isotope dilution gas chromatography-mass spectrometry with selective ion monitoring. After either treatment, drug concentrations were significantly (P < 0.05) decreased in both the SRM sample and the hair from authentic abusers. In the SRM groups, 6-67% of the original concentration remained after a single chemical treatment. Similarly, only 5-30% of the original concentration remained in authentic drug hairs that had formerly tested positive for COC, BZE and CE. Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  10. Fast and accurate pressure-drop prediction in straightened atherosclerotic coronary arteries.

    PubMed

    Schrauwen, Jelle T C; Koeze, Dion J; Wentzel, Jolanda J; van de Vosse, Frans N; van der Steen, Anton F W; Gijsen, Frank J H

    2015-01-01

    Atherosclerotic disease progression in coronary arteries is influenced by wall shear stress. To compute patient-specific wall shear stress, computational fluid dynamics (CFD) is required. In this study we propose a method for computing the pressure-drop in regions proximal and distal to a plaque, which can serve as a boundary condition in CFD. As a first step towards exploring the proposed method we investigated ten straightened coronary arteries. First, the flow fields were calculated with CFD and velocity profiles were fitted on the results. Second, the Navier-Stokes equation was simplified and solved with the found velocity profiles to obtain a pressure-drop estimate (Δp (1)). Next, Δp (1) was compared to the pressure-drop from CFD (Δp CFD) as a validation step. Finally, the velocity profiles, and thus the pressure-drop were predicted based on geometry and flow, resulting in Δp geom. We found that Δp (1) adequately estimated Δp CFD with velocity profiles that have one free parameter β. This β was successfully related to geometry and flow, resulting in an excellent agreement between Δp CFD and Δp geom: 3.9 ± 4.9% difference at Re = 150. We showed that this method can quickly and accurately predict pressure-drop on the basis of geometry and flow in straightened coronary arteries that are mildly diseased.

  11. Three-Dimensional Analysis of Spiny Dendrites Using Straightening and Unrolling Transforms

    PubMed Central

    Morales, Juan; Benavides-Piccione, Ruth; Pastor, Luis; Yuste, Rafael; DeFelipe, Javier

    2014-01-01

    Current understanding of the synaptic organization of the brain depends to a large extent on knowledge about the synaptic inputs to the neurons. Indeed, the dendritic surfaces of pyramidal cells (the most common neuron in the cerebral cortex) are covered by thin protrusions named dendritic spines. These represent the targets of most excitatory synapses in the cerebral cortex and therefore, dendritic spines prove critical in learning, memory and cognition. This paper presents a new method that facilitates the analysis of the 3D structure of spine insertions in dendrites, providing insight on spine distribution patterns. This method is based both on the implementation of straightening and unrolling transformations to move the analysis process to a planar, unfolded arrangement, and on the design of DISPINE, an interactive environment that supports the visual analysis of 3D patterns. PMID:22644869

  12. Application of operational radiographic inspection method for flaw detection of blade straightener from polymeric composite materials

    NASA Astrophysics Data System (ADS)

    Anoshkin, A. N.; Osokin, V. M.; Tretyakov, A. A.; Potrakhov, N. N.; Bessonov, V. B.

    2017-02-01

    In the article on the example of the straightener blade made of polymer composite materials, discusses the advantages of using the method of microfocus X-ray for nondestructive testing of aviation products. Described basic types of defects characteristics occurring in a similar type parts both during their manufacture and during their operation, namely, interlayer delamination, pores and wrinkles. Peculiarities of microfocus X-ray are shown, which is the use of radiation sources with a focal spot size of less than 100 μm. These features make it possible to increase the details and therefore, to minimize the size of detected defects in transmission. On the basis of experimental studies were defined radiographic signs of major types of defects, typical for products made of polymeric composite materials. Calculated time costs of personnel required for high-resolution X-ray recording and evaluation of test results.

  13. Active self-correction of back posture in children instructed with 'straighten your back' command.

    PubMed

    Czaprowski, Dariusz; Pawłowska, Paulina; Stoliński, Lukasz; Kotwicki, Tomasz

    2014-10-01

    The ability to adopt the properly corrected body posture is one of the factors determining the effectiveness of therapeutic programmes. This study determined the active self-correction expressed by the change of sagittal spinal curvatures (in standing and sitting positions) in 249 children (136 females, 113 males, aged 10-14 years) instructed with 'straighten your back' command (SYB). Spinal curvatures (sacral slope-SS, lumbar lordosis-LL, global, lower and upper thoracic kyphosis-TK, LK, UK, respectively) were assessed using Saunders inclinometer. The assessment was done in spontaneous standing and sitting positions and in the positions adopted after the SYB. In a standing position SYB led to the significant (P < 0.001) increase in SS, and the significant (P < 0.01) decrease in LL, TK, LK, UK. In a sitting position SYB led to significant changes (P < 0.001) from kyphotic to lordotic position of SS and LL and to the significant (P < 0.001) reduction of TK (36.5° ± 10.8 vs. 23.5° ± 11) and the flattening of LK (15.2° ± 8.7 vs. 1.0° ± 8.4). There were gender-based discrepancy regarding active self-correction only for LL in a standing and UK in a sitting position. Females demonstrated a significant decrease in LL (P < 0.001). UK significantly increased only in males (P < 0.001). The 'straighten your back' command leads to moving the spine away from mid-range towards end range of motion. Therefore, the command should not be used to elicit the most optimal back posture. Further studies are needed to determine if the active self-correction is different in females and males. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Penile straightening maneuvers employed during penile prosthesis surgery: technical options and outcomes.

    PubMed

    Segal, R L; Cabrini, M R; Bivalacqua, T J; Burnett, A L

    2014-01-01

    Straightening maneuvers (SM), including manual penile modeling, tunical relaxing incisions and corporal reconstruction using grafting techniques, are occasionally required during inflatable penile prosthesis (IPP) implantation to ensure functional penile straightness. The aim of this study was to compare the outcomes of men undergoing SM employed during IPP implantation compared with those wherein these maneuvers were not required. A retrospective review of 391 patients undergoing IPP implantation at the Johns Hopkins Hospital from January 2000 to December 2011 was performed. Patients in whom some SM was employed (SM, n=93, 23.9% of the overall cohort) were compared with those for whom SM was not required (IPP group, n=298). Seven patients were excluded from final analysis (6 patients with IPPs inserted in neophalli (SM group), and 1 patient with incomplete data (IPP group). Patients in whom a SM was used were younger (55.4 vs 62.3 years), more likely to have Peyronie's disease, and less likely to have prostate cancer, radical prostatectomy or to have previously used erectile aids (all P<0.05). Mean operating room time in the SM group was longer (173.8 vs 152.9 min, P=0.003). Within the SM group, modeling was performed in 40 (43%), tunical relaxing incisions in 37 (39.8%) and tunical reconstruction in 16 (17.2%) (most commonly using allograft dermis or pericardium, or synthetic gore-tex grafts). There were no significant differences in terms of device infection (P=0.15), mechanical failure (P=0.23) or erosion (P=0.96). Although limited in size, this cohort study suggests that IPP implantation in men with penile deformity requiring complex reconstruction to achieve straightening may be done proficiently and without increased adverse outcome risk.

  15. Emergency radiology: straightening of the cervical spine in MDCT after trauma—a sign of injury or normal variant?

    PubMed Central

    Deak, Zsuszsanna; Krtakovska, Aina; Ruschi, Francesco; Kammer, Nora; Wirth, Stefan; Reiser, Maximilian; Geyer, Lucas

    2016-01-01

    Objective: To evaluate whether straightening of the cervical spine (C-spine) alignment after trauma can be considered a significant multidetector CT (MDCT) finding. Methods: 160 consecutive patients after C-spine trauma admitted to a Level 1 trauma centre received MDCT according to Canadian Cervical Spine Rule and National Emergency X-Radiography Utilization Study indication rule; subgroups with and without cervical collar immobilization (CCI +/−) were compared with a control group (n = 20) of non-traumatized patients. Two independent readers evaluated retrospectively the alignment, determined the absolute rotational angle of the posterior surface of C2 and C7 (ARA C2–7) and grouped the results for lordosis (<−13°), straight (−13 to +6°) and kyphosis (>+6°). Results: In the two CCI−/CCI+ study groups, the straight or kyphotic alignment significantly (p = 0.001) predominated over lordosis. The number of patients with straight C-spine alignment was higher in the CCI+ group (CCI+ 69% vs CCI− 49%, p = 0.05). A comparison of the CCI+ group vs the CCI− group revealed a slightly smaller number of kyphotic (10% vs 18%, p = 0.34) and lordotic (21% vs 33%, p = 0.33) alignments. Statistically, however, the differences were of no significance. The control group revealed no significant differences. Conclusion: Straightening of the C-spine alone is not a definitive sign of injury but is a biomechanical variation due to CCI and neck positioning during MDCT or active patient control. Advances in knowledge: Straightening of the C-spine alignment in MDCT alone is not a definitive sign of injury. Straightening of the C-spine alignment is related to neck positioning and active patient control. CCI has a straightening effect on the cervical alignment. PMID:26764283

  16. Transmembrane Helix Straightening and Buckling Underlies Activation of Mechanosensitive and Thermosensitive K2P Channels

    PubMed Central

    Lolicato, Marco; Riegelhaupt, Paul M.; Arrigoni, Cristina; Clark, Kimberly A.; Minor, Daniel L.

    2014-01-01

    SUMMARY Mechanical and thermal activation of ion channels is central to touch, thermosensation, and pain. The TRAAK/TREK K2P potassium channel subfamily produces background currents that alter neuronal excitability in response to pressure, temperature, signaling lipids, and anesthetics. How such diverse stimuli control channel function is unclear. Here we report structures of K2P4.1 (TRAAK) bearing C-type gate-activating mutations that reveal a tilting and straightening of the M4 inner transmembrane helix and a buckling of the M2 transmembrane helix. These conformational changes move M4 in a direction opposite to that in classical potassium channel activation mechanisms and open a passage lateral to the pore that faces the lipid bilayer inner leaflet. Together, our findings uncover a unique aspect of K2P modulation, indicate a means for how the K2P C-terminal cytoplasmic domain affects the C-type gate which lies ~40Å away, and suggest how lipids and bilayer inner leaflet deformations may gate the channel. PMID:25500157

  17. Analytical treatment of electron trajectory straightener issues in free-electron lasers

    SciTech Connect

    Elliott, C.J.; Quimby, D.C.; Spectra Technology, Inc., Bellevue, WA )

    1989-01-01

    The poincare orbit of the electron's journey must be straight and narrow through a many period FEL. To utilize an available technology level, the straightest wiggler orbit operating point (SWOOP) is chosen by adjusting the spacing parameter of an orbit correction scheme. This eases the requirements for achieving the full potential of FEL wigglers. One quality index, one cost index, two quality factors, two measures of field noise, an improvement index, and a straightener classification scheme are concepts that facilitate the analysis. Only when the field noise is large, is this analysis of direct use. A reader-friendly description culminates in the comparison of two schemes to illustrate the methods. Two coupled first order langevin equations have solutions that are proven to be gaussian variables. The solutions are used to give the required cross correlations. These results are coupled with a simple graphical technique and give an expression for the angular variance in the correction corridor. The two components of this variance are compared to a fiducial scheme and yield the two quality factors from which the quality, improvement and cost indices are computed. 68 refs., 5 figs.

  18. Classification of masses on mammograms using rubber-band straightening transform and feature analysis

    NASA Astrophysics Data System (ADS)

    Sahiner, Berkman; Chan, Heang-Ping; Petrick, Nicholas; Helvie, Mark A.; Adler, Dorit D.; Goodsitt, Mitchell M.

    1996-04-01

    A new rubber-band straightening transform (RBST) and texture analysis were developed for classification of masses on mammograms as malignant or benign. A database of 168 mammograms containing biopsy-proven malignant and benign breast masses was digitized at a pixel size of 100 micrometer by 100 micrometer. Regions of interest (ROIs) containing a single mass from each mammogram were extracted by an experienced radiologist. A clustering algorithm was employed for automatic segmentation of each ROI into a mass object and background tissue. A 40-pixel-wide region of the gray-scale image surrounding the mass was transformed onto the Cartesian plane using RBST. The first row of the transformed image contained the pixels along the mass edge. The jth row of the transformed image contained the pixel values at a distance of j pixels from the edge in the normal direction to the edge contour. In the RBST image, mass margins appeared as approximately horizontal edges, and spiculations appeared as approximately vertical lines. Thus, edge sharpness and possible spiculations could be better characterized with directional texture measures. Texture features were extracted from spatial gray-level dependence matrices calculated from the RBST images. Linear discriminant analysis was used for classification, and receiver operating characteristic (ROC) analysis was used to evaluate the classification accuracy. The area Az under the test ROC curve reached 0.87 using cross-validation and 0.89 using the leave-one-case-out method.

  19. Elevated formaldehyde concentration in "Brazilian keratin type" hair-straightening products: a cross-sectional study.

    PubMed

    Maneli, Mbulelo H; Smith, Peter; Khumalo, Nonhlanhla P

    2014-02-01

    Brazilian keratin treatment (BKT) and similar straightening products fix and retain a straight shape even when the hair is wet. Unacceptably high concentrations of formaldehyde have been reported in such products. We sought to measure the formaldehyde concentration in all BKT brands marketed in South Africa in 2012. We quantified formaldehyde by high-performance liquid chromatography with ultraviolet light detection after derivatization with dinitrophenylhydrazine. All components of 7 identified commercial brands were each tested 3 times. The maximum safe concentration of formaldehyde set by the US Cosmetic Ingredient Review Expert Panel is less than 0.2%. Of the 7 commercial BKT brands, 6 had formaldehyde levels that ranged from 0.96% to 1.4%, ie, 5 times higher than the recommended level; these included 5 brands labeled formaldehyde-free. The study is limited by not including all internationally available BKT products. Formaldehyde concentrations in BKT products may exceed recommended levels and serve as a health hazard. Industry monitoring is needed to improve compliance and protection of hairdressers and consumers. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  20. Transmembrane helix straightening and buckling underlies activation of mechanosensitive and thermosensitive K(2P) channels.

    PubMed

    Lolicato, Marco; Riegelhaupt, Paul M; Arrigoni, Cristina; Clark, Kimberly A; Minor, Daniel L

    2014-12-17

    Mechanical and thermal activation of ion channels is central to touch, thermosensation, and pain. The TRAAK/TREK K(2P) potassium channel subfamily produces background currents that alter neuronal excitability in response to pressure, temperature, signaling lipids, and anesthetics. How such diverse stimuli control channel function is unclear. Here we report structures of K(2P)4.1 (TRAAK) bearing C-type gate-activating mutations that reveal a tilting and straightening of the M4 inner transmembrane helix and a buckling of the M2 transmembrane helix. These conformational changes move M4 in a direction opposite to that in classical potassium channel activation mechanisms and open a passage lateral to the pore that faces the lipid bilayer inner leaflet. Together, our findings uncover a unique aspect of K(2P) modulation, indicate a means for how the K(2P) C-terminal cytoplasmic domain affects the C-type gate which lies ∼40Å away, and suggest how lipids and bilayer inner leaflet deformations may gate the channel.

  1. Biomechanical differences in the stem straightening process among Pinus pinaster provenances. A new approach for early selection of stem straightness.

    PubMed

    Sierra-de-Grado, Rosario; Pando, Valentín; Martínez-Zurimendi, Pablo; Peñalvo, Alejandro; Báscones, Esther; Moulia, Bruno

    2008-06-01

    Stem straightness is an important selection trait in Pinus pinaster Ait. breeding programs. Despite the stability of stem straightness rankings in provenance trials, the efficiency of breeding programs based on a quantitative index of stem straightness remains low. An alternative approach is to analyze biomechanical processes that underlie stem form. The rationale for this selection method is that genetic differences in the biomechanical processes that maintain stem straightness in young plants will continue to control stem form throughout the life of the tree. We analyzed the components contributing most to genetic differences among provenances in stem straightening processes by kinetic analysis and with a biomechanical model defining the interactions between the variables involved (Fournier's model). This framework was tested on three P. pinaster provenances differing in adult stem straightness and growth. One-year-old plants were tilted at 45 degrees, and individual stem positions and sizes were recorded weekly for 5 months. We measured the radial extension of reaction wood and the anatomical features of wood cells in serial stem cross sections. The integral effect of reaction wood on stem leaning was computed with Fournier's model. Responses driven by both primary and secondary growth were involved in the stem straightening process, but secondary-growth-driven responses accounted for most differences among provenances. Plants from the straight-stemmed provenance showed a greater capacity for stem straightening than plants from the sinuous provenances mainly because of (1) more efficient reaction wood (higher maturation strains) and (2) more pronounced secondary-growth-driven autotropic decurving. These two process-based traits are thus good candidates for early selection of stem straightness, but additional tests on a greater number of genotypes over a longer period are required.

  2. An overview of chemical straightening of human hair: technical aspects, potential risks to hair fibre and health and legal issues.

    PubMed

    Miranda-Vilela, A L; Botelho, A J; Muehlmann, L A

    2014-02-01

    Personal image, as it relates to external beauty, has attracted much attention from the cosmetic industry, and capillary aesthetics is a leader in consumption in this area. There is a great diversity of products targeting both the treatment and beautification of hair. Among them, hair straighteners stand out with a high demand by costumers aiming at beauty, social acceptance and ease of daily hair maintenance. However, this kind of treatment affects the chemical structure of keratin and of the hair fibre, bringing up some safety concerns. Moreover, the development of hair is a dynamic and cyclic process, where the duration of growth cycles depends not only on where hair grows, but also on issues such as the individual's age, dietary habits and hormonal factors. Thus, although hair fibres are composed of dead epidermal cells, when they emerge from the scalp, there is a huge variation in natural wave and the response to hair cosmetics. Although it is possible to give the hair a cosmetically favourable appearance through the use of cosmetic products, for good results in any hair treatment, it is essential to understand the mechanisms of the process. Important information, such as the composition and structure of the hair fibres, and the composition of products and techniques available for hair straightening, must be taken into account so that the straightening process can be designed appropriately, avoiding undesirable side effects for hair fibre and for health. This review aims to address the morphology, chemical composition and molecular structure of hair fibres, as well as the products and techniques used for chemical hair relaxing, their potential risk to hair fibre and to health and the legal aspects of their use. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  3. Measuring OutdoorAir Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners

    SciTech Connect

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2008-10-01

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100percent, and were often greater than 25percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  4. Environmental and biological monitoring of occupational formaldehyde exposure resulting from the use of products for hair straightening.

    PubMed

    Peteffi, Giovana Piva; Antunes, Marina Venzon; Carrer, Caroline; Valandro, Eduarda Trevizani; Santos, Sílvia; Glaeser, Jéssica; Mattos, Larissa; da Silva, Luciano Basso; Linden, Rafael

    2016-01-01

    The evaluation of formaldehyde (FD) exposure in beauty salons, due to the use of hair straightening products, and its relation with genotoxicity biomarkers was performed in this study. Regardless of official recommendations, the inappropriate use of homemade hair creams has became a popular practice in Brazil, and high formaldehyde content in the "progressive straightening" creams can contain mutagens that could increase the incidence of neoplasia in those people who use them. Damage to DNA was assessed by conducting a micronuclei test (MNT) on buccal cells and the comet assay on heparinized venous blood samples. A total of 50 volunteers were recruited at six different beauty salons (labeled A to F). At two salons that used products that did not contain FD (salons D and E), environmental FD concentrations were 0.04 and 0.02 ppm. In contrast, the products used at salons A, B, C, and F contained 5.7, 2.61, 5.9, and 5.79% of FD, and these salons had environmental FD concentrations of 0.07, 0.14, 0.16, and 0.14 ppm, respectively. Comparison of the beauty salon workers from each of the six beauty salons revealed significant differences in urinary formic acid (FA) concentration before exposure (p = 0.016), urinary FA after exposure (p = 0.004), variation in FA concentration before and after exposure (p = 0.018), environmental FD concentration (p < 0.001), cytogenetic damage detected by the comet assay according to both damage index (p < 0.001) and frequency of damage (p < 0.001), and for karyorrhexis only according to the MNT (p = 0.001).

  5. Novel analytical method to measure formaldehyde release from heated hair straightening cosmetic products: Impact on risk assessment.

    PubMed

    Galli, Corrado Lodovico; Bettin, Federico; Metra, Pierre; Fidente, Paola; De Dominicis, Emiliano; Marinovich, Marina

    2015-08-01

    Hair straightening cosmetic products may contain formaldehyde (FA). In Europe, FA is permitted for use in personal care products at concentrations ⩽ 0.2g/100g. According to the Cosmetic Ingredient Review (CIR) Expert Panel products are safe when formalin (a 37% saturated solution of FA in water) concentration does not exceed 0.2g/100g (0.074 g/100g calculated as FA). The official method of reference does not discriminate between "free" FA and FA released into the air after heating FA donors. The method presented here captures and collects the FA released into the air from heated cosmetic products by derivatization with 2,4-dinitrophenylhydrazine and final analysis by UPLC/DAD instrument. Reliable data in terms of linearity, recovery, repeatability and sensitivity are obtained. On a total of 72 market cosmetic products analyzed, 42% showed FA concentrations very close to or above the threshold value (0.074 g/100g calculated as FA) suggested by the Cosmetic Ingredient Review committee, whereas 11 products, negative using the official method of reference, were close to or above the threshold value (0.074 g/100g calculated as FA). This may pose a health problem for occasional users and professional hair stylists. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. The Influence of the “Straighten Your Back” Command on the Sagittal Spinal Curvatures in Children with Generalized Joint Hypermobility

    PubMed Central

    Pawłowska, Paulina; Kolwicz-Gańko, Aleksandra; Sitarski, Dominik

    2017-01-01

    Objectives. The aim of the study was to assess the change of sagittal spinal curvatures in children with generalized joint hypermobility (GJH) instructed with “straighten your back” command (SYB). Methods. The study included 56 children with GJH. The control group consisted of 193 children. Sacral slope (SS), lumbar lordosis (LL), global thoracic kyphosis (TK), lower thoracic kyphosis (LK), and upper thoracic kyphosis (UK) were assessed with Saunders inclinometer both in spontaneous positions (standing and sitting) and after the SYB. Results. Children with GJH after SYB presented the following: in standing, increase in SS and decrease in TK, LK, and UK (P < 0.01), with LL not significantly changed; in sitting: decrease in global thoracic kyphosis (35.5° (SD 20.5) versus 21.0° (SD 15.5), P < 0.001) below the standards proposed in the literature (30–40°) and flattening of its lower part (P < 0.001). The same changes were observed in the control group. Conclusions. In children with generalized joint hypermobility, the “straighten your back” command leads to excessive reduction of the global thoracic kyphosis and flattening of its lower part. Therefore, the “straighten your back” command should not be used to achieve the optimal standing and sitting positions. PMID:28116313

  7. Contribution of the straightening effect of the parent artery to decreased recanalization in stent-assisted coiling of large aneurysms.

    PubMed

    Ishii, Akira; Chihara, Hideo; Kikuchi, Takayuki; Arai, Daisuke; Ikeda, Hiroyuki; Miyamoto, Susumu

    2016-12-23

    OBJECTIVE The durability of embolization of large aneurysms is enhanced by use of the neck-bridging stent. However, it remains unclear what factors contribute to decreased recanalization. The purpose of this study was to demonstrate the contribution of the straightening effect of the parent artery to the durability of stent-assisted coiling for large aneurysms. METHODS Of the 182 aneurysms treated by embolization since the introduction of the neurovascular stent, 82 consecutive unruptured aneurysms with a diameter greater than 7 mm were selected. There were 52 aneurysms treated with a stent (Group S) and 30 treated without a stent (Group NS). Occlusion status was evaluated 12 months after embolization with digital subtraction angiography. The vascular angle of the parent artery was measured before, immediately after, and 12 months after embolization. The rates of recanalization were compared between Group S and Group NS. In Group S, the rates of recanalization were further compared between those aneurysms with and without a significant angle change. RESULTS The rate of major recanalization was 9.6% in Group S and 26.7% in Group NS. The volume embolization ratio was 32.6% in Group S and 31.6% in Group NS, with no statistically significant difference. However, the angulation change before and after coiling was significantly higher in Group S (10.6°) than in Group NS (0.9°). The difference in the angulation was more evident 12 months after coiling (19.1° in Group S and 1.5° in Group NS). In Group S, recanalization was found in 14.3% of 35 stented aneurysms without a significant angular change when a significant angular change was defined as more than 20°. In contrast, all 17 aneurysms with ≥ 20° of angular change remained occluded. CONCLUSIONS Significant angular change of ≥ 20° most likely leads to decreased recanalization following stent-assisted embolization of large aneurysms.

  8. Hair straightener poisoning

    MedlinePlus

    ... if known) Time it was swallowed Amount swallowed Poison Control Your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere ...

  9. Straightening Out Learning Curves

    ERIC Educational Resources Information Center

    Corlett, E. N.; Morecombe, V. J.

    1970-01-01

    The basic mathematical theory behind learning curves is explained, together with implications for clerical and industrial training, evaluation of skill development, and prediction of future performance. Brief studies of textile worker and typist training are presented to illustrate such concepts as the reduction fraction (a consistent decrease in…

  10. Misoprostol versus uterine straightening by bladder distension for pain relief in postmenopausal patients undergoing diagnostic office hysteroscopy: a randomised controlled non-inferiority trial.

    PubMed

    Fouda, Usama M; Elshaer, Hesham S; Elsetohy, Khaled A; Youssef, Mohamed A

    2016-08-01

    To compare the effectiveness of misoprostol with uterine straightening by bladder distension in minimising the pain experienced by postmenopausal patients during diagnostic office hysteroscopy. Seventy-six postmenopausal patients were randomly allocated in a 1:1 ratio to the misoprostol group or to the bladder distension group. Patients in the misoprostol group were instructed to insert two misoprostol tablets (400μg) in the vagina 12h before office hysteroscopy. Patients in the bladder distension group were instructed to drink one litre of water and to avoid urination during a period of 2h before office hysteroscopy. The severity of pain experienced by the patients during and at 30min after the procedure was measured using a 100-mm visual analogue scale (VAS). The ease of passing the hysteroscope through the cervical canal was assessed by the hysteroscopists using a 100-mm VAS. The passage of the hysteroscope through the cervical canal was easier in the misoprostol group [60.37±15.78 vs. 50.05±19.88, p=0.015]. The mean VAS pain score during the procedure was significantly lower in the misoprostol group [39.47±13.96 vs. 50.18±15.44, p=0.002]. The mean VAS pain score 30min post-procedure was comparable between both groups [11.82±3.71 vs. 12.61±4.06, p=0.379]. Vaginal misoprostol is more effective than uterine straightening by bladder distension in relieving the pain experienced by postmenopausal patients during office hysteroscopy. Clinicaltrials.gov [NCT02328495]. https://clinicaltrials.gov/ct2/show/NCT02328495. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Numerical modeling of gravel bed river response to meander straightening: The coupling between the evolution of bed pavement and long profile

    NASA Astrophysics Data System (ADS)

    Talbot, Tracey; Lapointe, Michel

    2002-06-01

    Artificial meander straightening (rectification) was conducted in the early 1960s along the Sainte-Marguerite River, Canada, in order to facilitate highway construction along the valley. Previous studies [Talbot and Lapointe, 2002] confirm that vertical reprofiling, coupled with pavement coarsening in the degrading reach, were the main responses counteracting the disequilibrium in gravel transport rates triggered at rectification of this system. Numerical simulations, using SEDROUT2.0, a one-dimensional hydraulic and sediment transport model, and validated against the observed channel response, show the important role played by an advancing wave of pavement coarsening down the rectified reach in modulating the bed degradation response. Simulations extending into the future reveal an asymptotically slowing approach to equilibrium in the middle of the 21st century, with a response half-time of the order of 10 years. In near-threshold gravel bed systems like the Sainte-Marguerite River, pavement coarsening after rectification buffers the system against extreme degradation. Most significantly for watershed management, this also appears to severely limit the extent of propagation of degradation upstream of the rectification.

  12. Effect of Temperature and Velocity of Pressing on Grain Refinement in AA5083 Aluminum Alloy During Repetitive Corrugation and Straightening Process

    NASA Astrophysics Data System (ADS)

    Thangapandian, N.; Balasivanandha Prabu, S.; Padmanabhan, K. A.

    2016-12-01

    Repetitive corrugation and straightening experiments were carried out on sheets of aluminum alloy, AA5083, at room temperature and 573 K (300 °C) and two pressing velocities (0.5 and 2 mm/s). In every case, the sheet was processed to the maximum possible number of passes. Electron backscattered diffraction analysis and transmission electron microscopy were used to characterize microstructure evolution. After room temperature processing with a pressing velocity of 0.5 mm/s, the average grain size had decreased to 11 microns from 45 microns, with 70 pct of the grain boundaries of the high-angle type. In contrast, sub-grain formation was present at a pressing velocity of 2 mm/s. Mechanical properties like tensile strength and hardness were correlated with microstructures. It is concluded that the velocity of pressing plays a crucial role in grain refinement and recovery and the resulting mechanical properties, as the time available for dislocation rearrangements during processing depends strongly on this variable. An increase in temperature of deformation leads to softening and a deterioration in the mechanical properties.

  13. Flame Straightening Quenched-and-Tempered Steels in Ship Construction

    DTIC Science & Technology

    1974-01-01

    handling. Either an annular or single stream quench can be used. Temperature Measurement Tempe, ire-indicating crayons melting at 900 F and 1050 F...should be checked periodically by removing the torch and applying the temperature-indicating crayons simultaneously and quickly. The 900 F crayon should... melt , but the 050 F one should not. As an additional check on temperature, no obvious color should be visible immediately after removing the torch

  14. Straightening out Earth System Sensitivity Across the Late Pleistocene and Pliocene

    NASA Astrophysics Data System (ADS)

    Huybers, P. J.

    2015-12-01

    There are good reasons to expect feedback strengths to alter with changes in background climate, but empirically constrainting such changes is difficult. Earth System Sensitivity (ESS) --- which accounts for both fast and slow feedbacks in the climate system, including those associated with ice sheets and vegetation --- is relatively well constrained for the Late Pleistocene because of accurate and well-resolved records of temperature and greenhouse gas concentration. The Pliocene offers the geologically most recent epoch during which to examine ESS in warmer climates, but empirical estimates have come to conflicting results. Estimates relying on mean changes in Pliocene temperature and CO2 concentration find ESS values consistent with those from the Late Pleistocene, whereas more recent estimates from variability within the Pliocene find ESS values of half the magnitude, implying that ESS bends downward with increased global temperature. This set of observations might be physically self-consistent, for example, if within-Pliocene ESS reflects a smaller ice-albedo feedback, whereas average Pliocene temperature reflects warmer conditions brought about by a singular ocean-atmospheric transition resulting from higher greenhouse gas concentrations. Another possibility is that discrepancies result from errors in some or all of the ESS estimates. ESS may be overestimated if temperature changes are misattributed to greenhouse gases, when instead, for example, they are driven by changes in orbital variations or opening of oceanic passages. Alternatively, ESS may be underestimated because errors in forcing and misalignment of age models generally result in a statistical bias termed regression dilution. Here a method for optimally aligning age models is coupled with a spectral regression technique in order to account for age model uncertainty and delineate contributions from orbital variations. The method is applied to within-Pleistocene and within-Pliocene temperature and greenhouse gas variations, and preliminary results indicate lower Pleistocene ESS, higher Pliocene ESS, and greater uncertainties than previously indicated, all of which make ESS estimates across colder and warmer climates less inconsistent.

  15. Straightening out the queer? Same-sex experience and attraction among young people in Norway.

    PubMed

    Hegna, Kristinn; Larsen, Camilla Jordheim

    2007-01-01

    The aim of this study was to describe the prevalence of same-sex experience, from deep kissing, through petting to genital contact, same-sex romantic attraction and reported same-sex arousal in a representative sample of young men and women aged 17-18 in Norway. While same-sex experiences were reported as being more prevalent among young women (27.4%) than among young men (6.5%), the gender difference in the case of same-sex genital experiences was smaller (F = 4.6%, M = 2.7%) than in the case of deep kissing (F = 25.7%, M = 3.9%). While same-sex romantic attraction was more prevalent among young men with same-sex experiences than young women, such attraction was confined to a minority of all young men. Results suggest that same-sex experiences among Norwegian youth are not unequivocally tied to same-sex attraction and possible homosexual self-identity. We argue that among young men, same-sex behaviour is more often associated with same-sex orientation whereas young women's same-sex relations seem to be more exploratory.

  16. Development of new microwave-drying and straightening technology for low-value curved timber

    Treesearch

    John F. Hunt; Hongmei Gu; Philip Walsh; Jerrold E. Winandy

    2005-01-01

    A considerable amount of small-diameter, branched, or curved timber is currently left standing, bucked and left on the ground, chipped, or burned after logging or thinning operations. Most North American mills are not equipped to handle this low-value material. In many areas of the western United States, such forest residue does not decompose and becomes susceptible to...

  17. Thin section casting program. Volume 4: Static cast product bending, straightening, and rolling

    NASA Astrophysics Data System (ADS)

    1989-01-01

    Statically cast 1/2 in., 3/4 in., and 1 in. thick steel slabs were subjected to hot rolling in a laboratory reversing mill and to simulated coiling-uncoiling on a three-point bender-unbender. Tensile properties and microstructures of hot bands thinner than 0.15 in. produced from the statically cast slabs were found to be independent of initial slab thickness and similar to those from conventionally cast 8 to 10 in. thick slabs. Cold rolled and batch annealed product from the statically cast slabs had mechanical properties equivalent to those of conventionally processed deep-drawing quality steel. Overall, the results of this task indicated that 1/2 to 1 in. thick steel sections produced in a twin belt caster can be coiled and uncoiled in a hot coiler box downstream of the caster without generating any cracks in the product, and that the total range of hot and cold rolled sheet and strip products with qualities equivalent to those of conventionally produced can be obtained from the 1/2 in. to 1 in. thick sections. This report is the fifth of a six volume set on thin section casting.

  18. Process for straightening and drying southern pine 2 by 4's in 24 hours

    Treesearch

    Peter Koch

    1971-01-01

    In 21 hours under mechanical restraint and in a kiln providing a cross-circulation velocity of 1,000 f.p.m. at dry-and wet-bulb temperatures of 240 and 160oF., followed by 3 hours at 195 and 185oF., southern pine 2 by 4 studs cut from steamed veneer cores or small logs were dried to 9-percent moisture content (Standard...

  19. DIY Teeth-Straightening: Don't Try This At Home

    MedlinePlus

    ... This at Home Dangers lurk when rubber bands, paper clips and other tools are used to avoid ... potentially dangerous objects such as rubber bands, string, paper clips and fake retainers to circumvent the orthodontists' ...

  20. Characterization of formaldehyde exposure resulting from the use of four professional hair straightening products.

    PubMed

    Pierce, J S; Abelmann, A; Spicer, L J; Adams, R E; Glynn, M E; Neier, K; Finley, B L; Gaffney, S H

    2011-11-01

    An exposure simulation study was conducted to characterize potential formaldehyde exposures of salon workers and clients during keratin hair smoothing treatments. Four different hair treatment brands (Brazilian Blowout, Coppola, Global Keratin, and La Brasiliana) were applied to separate human hair wigs mounted on mannequin heads. Short-term (6-16 min) and long-term (41-371 min) personal and area samples (at distances of 0.5 to 3.0 m from the source) were collected during each treatment for the 1-day simulation. A total of 88 personal, area, and clearance samples were collected. Results were analyzed based on task sampling (blow-dry, flat-iron), treatment sampling (per hair product), and time-weighted averages (per hair treatment, four consecutive treatments). Real-time monitoring of tracer gas levels, for determining the air exchange rate, and formaldehyde levels were logged throughout the simulation. Bulk samples of each hair treatment were collected to identify and quantify formaldehyde and other chemical components that may degrade to formaldehyde under excessive heat. Mean airborne concentrations of formaldehyde ranged from 0.08-3.47 ppm during blow-dry and 0.08-1.05 ppm during flat-iron. During each treatment, the mean airborne concentrations ranged from 0.02-1.19 ppm throughout different zones of the salon. Estimated 8-hr time-weighted averages for one treatment per day ranged from 0.02 ppm for La Brasiliana to 0.08-0.16 ppm for Brazilian Blowout. For four treatments per day, means ranged from 0.04-0.05 ppm for La Brasiliana to 0.44-0.75 ppm for Brazilian Blowout. Using all four products in one day resulted in estimated 8-hr time-weighted averages ranging from 0.17-0.29 ppm. Results from bulk sampling reported formaldehyde concentrations of 11.5% in Brazilian Blowout, 8.3% in Global Keratin, 3% in Coppola, and 0% in La Brasiliana. Other products that degrade into formaldehyde were detected in Global Keratin, Coppola, and La Brasiliana. The results of this study show that professional hair smoothing treatments--even those labeled "formaldehyde-free"--have the potential to produce formaldehyde concentrations that meet or exceed current occupational exposure limits.

  1. Straightening of a wavy strip: An elastic-plastic contact problem including snap-through

    NASA Technical Reports Server (NTRS)

    Fischer, D. F.; Rammerstorfer, F. G.

    1980-01-01

    The nonlinear behavior of a wave like deformed metal strip during the levelling process were calculated. Elastic-plastic material behavior as well as nonlinearities due to large deformations were considered. The considered problem lead to a combined stability and contact problem. It is shown that, despite the initially concentrated loading, neglecting the change of loading conditions due to altered contact domains may lead to a significant error in the evaluation of the nonlinear behavior and particularly to an underestimation of the stability limit load. The stability was examined by considering the load deflection path and the behavior of a load-dependent current stiffness parameter in combination with the determinant of the current stiffness matrix.

  2. Construction Norms Straightened. Part II. Section D. Gas Supply External Networks and Constructions of the Norm of Planning. Chapter 13,

    DTIC Science & Technology

    1980-05-16

    purpose of expendable gas. (3). Unit measurement. t). Gas tlo in thousand of kcal. (5). I. Hatitable buildings. (6). 7cr prxearation of food (in...presence in apartment of gas stove and centralized hct water supply). (7). To 1 persons per annum. (8). Per pieparation ef food and hot water for economic...For preparation of food and hot water fcr economic and health and kygiene needs without washing of linen (when in apartment of gas stcie dad gas cf

  3. Let's Get This Straightened Out: Finding a Place and Presence for Sexual/Gender Identity-Difference in Peace Education

    ERIC Educational Resources Information Center

    Mizzi, Robert

    2010-01-01

    Expressions of homo/transphobia continue to rupture and sometimes even erase the lives of persons with sexual/gender identity-difference across the globe. Despite this, experiences with violence of this nature largely go unexamined in peace education scholarship. In order to begin a discussion about sexuality/gender identity-difference within a…

  4. Straighten the Back to Sit: Belly-Cultivation Techniques as "Modern Health Methods" in Japan, 1900-1945.

    PubMed

    Wu, Yu-Chuan

    2016-09-01

    In Japan, the first half of the twentieth century saw a remarkable revival of concern with the cultivation of the belly, with a variety of belly-cultivation techniques, particularly breathing exercise and meditative sitting, widely practiced for improving health and treating diseases. This article carefully examines some practitioners' experiences of belly-cultivation practice in attempting to understand its healing effects for them within their life histories and contemporary intellectual, social and cultural contexts. It shows that belly-cultivation practice served as a medium for some practitioners to reflect on and retell their life stories, and that the personal charisma of certain masters and the communities developing around them provided practitioners with a valuable sense of belonging in an increasingly industrialized and urbanized society. Moreover, these belly-cultivation techniques provided an embodied way for some to explore and affirm their sense of self and develop individual identity. While they were increasingly promoted as cultural traditions capable of cultivating national character, they also served as healing practices by inspiring practitioners with a sense of collective identity and purpose. With these analyses, this article sheds light on the complicated meanings of belly-cultivation for practitioners, and provides illustrative examples of the multitude of meanings of the body, bodily cultivation and healing.

  5. Active self-correction of spinal posture in pain-free women in response to the command "straighten your back".

    PubMed

    Barczyk-Pawelec, Katarzyna; Sipko, Tomasz

    2016-10-04

    Evidence is limited regarding the regional changes in spinal posture after self-correction. The aim of the present study was to evaluate whether active self-correction improved standing and sitting spinal posture. Photogrammetry was used to assess regional spinal curvatures and vertical global spine orientation (GSO) in 42 asymptotic women aged 20-24 years. Upper thoracic spine angle and GSO increased in response to self-correction, while the thoracolumbar and lumbosacral angles decreased. Self-correction in the standing position resulted in decreased inclination of the upper thoracic and thoracolumbar spinal angles. Correction of sitting posture reduced the angle of the upper thoracic spine and GSO. The effects of active self-correction on spinal curvature and GSO were different for the standing versus sitting position; the greatest effects of active correction were noted in the thoracic spine. Balanced and lordotic postures were most prevalent in the habitual and actively self-corrected standing positions, whereas the kyphotic posture was most prevalent in the habitual sitting position, indicative that self-correction back posture in the standing position could be an important health-related daily activity, especially during prolonged sitting.

  6. Let's Get This Straightened Out: Finding a Place and Presence for Sexual/Gender Identity-Difference in Peace Education

    ERIC Educational Resources Information Center

    Mizzi, Robert

    2010-01-01

    Expressions of homo/transphobia continue to rupture and sometimes even erase the lives of persons with sexual/gender identity-difference across the globe. Despite this, experiences with violence of this nature largely go unexamined in peace education scholarship. In order to begin a discussion about sexuality/gender identity-difference within a…

  7. Cold Saw Operator (iron & steel) 6-88.651; Cold Sizing Mill Operator (iron & steel) 4-88.315; Decambering Mill Operator (iron & steel) 6-88.346; Flying Cut-Off Machine Operator (iron & steel) 6-88.655; Rotary Straightener Operator (iron & steel) 6-88.346; Straightener Machine Operator (iron & steel) 6-88.354; Tube Straightener Operator (iron & steel) 6-88.346; Welder (iron & steel) 4-88.343; Welder, Assistant (iron & steel) 4-88.344--Technical

    ERIC Educational Resources Information Center

    Manpower Administration (DOL), Washington, DC. U.S. Training and Employment Service.

    The United States Training and Employment Service General Aptitude Test Battery (GATB), first published in 1947, has been included in a continuing program of research to validate the tests against success in many different occupations. The GATB consists of 12 tests which measure nine aptitudes: General Learning Ability; Verbal Aptitude; Numerical…

  8. Disappearance of a small intracranial aneurysm as a result of vessel straightening and in-stent stenosis following use of an Enterprise vascular reconstruction device.

    PubMed

    Takemoto, Koichiro; Tateshima, Satoshi; Rastogi, Sachin; Gonzalez, Nestor; Jahan, Reza; Duckwiler, Gary; Vinuela, Fernando

    2013-01-17

    In-stent stenosis after stent-assisted coil embolization is a rare but well-known complication. A 32-year-old woman with an unruptured wide-necked left internal carotid artery (ICA) terminus aneurysm and an ipsilateral very small anterior choroidal artery aneurysm underwent stent-assisted coil embolization for the ICA terminus aneurysm. The 4-month follow-up angiography revealed diffuse in-stent stenosis and disappearance of the untreated anterior choroidal artery aneurysm, retaining the patency of the anterior choroidal artery. To our knowledge, this is the first report to demonstrate the course of in-stent stenosis and disappearance of an untreated small intracranial aneurysm as a result. We report this unique case and discuss the interesting mechanism underlying this phenomenon, and also provide a review of the relevant literature.

  9. Disappearance of a small intracranial aneurysm as a result of vessel straightening and in-stent stenosis following use of an Enterprise vascular reconstruction device.

    PubMed

    Takemoto, Koichiro; Tateshima, Satoshi; Rastogi, Sachin; Gonzalez, Nestor; Jahan, Reza; Duckwiler, Gary; Vinuela, Fernando

    2014-01-01

    In-stent stenosis after stent-assisted coil embolization is a rare but well-known complication. A 32-year-old woman with an unruptured wide-necked left internal carotid artery (ICA) terminus aneurysm and an ipsilateral very small anterior choroidal artery aneurysm underwent stent-assisted coil embolization for the ICA terminus aneurysm. The 4-month follow-up angiography revealed diffuse in-stent stenosis and disappearance of the untreated anterior choroidal artery aneurysm, retaining the patency of the anterior choroidal artery. To our knowledge, this is the first report to demonstrate the course of in-stent stenosis and disappearance of an untreated small intracranial aneurysm as a result. We report this unique case and discuss the interesting mechanism underlying this phenomenon, and also provide a review of the relevant literature.

  10. Separating rapid relocking, afterslip, and viscoelastic relaxation: An application of the postseismic straightening method to the Maule 2010 cGPS

    NASA Astrophysics Data System (ADS)

    Bedford, Jonathan; Moreno, Marcos; Li, Shaoyang; Oncken, Onno; Baez, Juan Carlos; Bevis, Michael; Heidbach, Oliver; Lange, Dietrich

    2016-10-01

    The postseismic deformation captured with continuous Global Positioning System (cGPS) monitoring following many recent megathrust events has been shown to be a signal composed of two dominant processes: afterslip on the plate interface and viscoelastic relaxation of the continental and oceanic mantles in response to the coseismic stress perturbation. Following the south central Chile 2010 Maule Mw 8.8 earthquake, the time series from the regional cGPS network show a distinct curvature in the pathway of the horizontal motion that is not easily fit by a stationary decaying pattern of afterslip in combination with viscoelastic relaxation. Here we show that with realistic assumptions about the long-term decay of the afterslip signal, the postseismic signal can be decomposed into three first-order contributing processes: plate interface relocking, plate interface afterslip, and mantle viscoelastic relaxation. From our analyses we conclude that the plate interface recovers its interseismic locking state rapidly (model space ranges between an instant recovery and a period of 1 year), a finding that supports laboratory experimental evidence as well as some recent studies of aftershocks and postseismic surface deformation. Furthermore, relocking is the main cause of the curvature in the cGPS signal, and this study presents a plausible range of geodetic relocking rates following a megathrust earthquake.

  11. Construction Norms Straightened. Part II. Section G, Chapter 12, Gas Supply, Gas-Distributing Stations, Cylinder and Reservoir Settings up of the Liquefied Gas of the Norm of Design, SNIP II-G.12-65.

    DTIC Science & Technology

    1980-05-19

    sinul-anecus prctaction of station tic& incioecce/impingement to its territcry of thawed and dcwnocur waterz zcu bltkcut. 2.11. During layoct or raxicad...of nearest reservoir, but not less than I a. 2.49. For removing downpour and thaw water from embanked territory in earth shaft cr sall must be...degree cf refractoriness (fcr example, theaters, cinemas , clubs, touses cf culture, therapeutic and childrengs institutions, educational institutions

  12. The crooked nose.

    PubMed

    Shipchandler, Taha Z; Papel, Ira D

    2011-04-01

    Straightening a crooked nose is a challenge. Several techniques exist ranging from simple to technically complex. It is important to approach the nose systematically and to remember that perfection may be impossible to achieve. If straightening is not attainable, softening grafts or onlay grafts should be used to camouflage subtle irregularities.

  13. Processivity of peptidoglycan synthesis provides a built-in mechanism for the robustness of straight-rod cell morphology

    PubMed Central

    Sliusarenko, Oleksii; Cabeen, Matthew T.; Wolgemuth, Charles W.; Jacobs-Wagner, Christine; Emonet, Thierry

    2010-01-01

    The propagation of cell shape across generations is remarkably robust in most bacteria. Even when deformations are acquired, growing cells progressively recover their original shape once the deforming factors are eliminated. For instance, straight-rod-shaped bacteria grow curved when confined to circular microchambers, but straighten in a growth-dependent fashion when released. Bacterial cell shape is maintained by the peptidoglycan (PG) cell wall, a giant macromolecule of glycan strands that are synthesized by processive enzymes and cross-linked by peptide chains. Changes in cell geometry require modifying the PG and therefore depend directly on the molecular-scale properties of PG structure and synthesis. Using a mathematical model we quantify the straightening of curved Caulobacter crescentus cells after disruption of the cell-curving crescentin structure. We observe that cells straighten at a rate that is about half (57%) the cell growth rate. Next we show that in the absence of other effects there exists a mathematical relationship between the rate of cell straightening and the processivity of PG synthesis—the number of subunits incorporated before termination of synthesis. From the measured rate of cell straightening this relationship predicts processivity values that are in good agreement with our estimates from published data. Finally, we consider the possible role of three other mechanisms in cell straightening. We conclude that regardless of the involvement of other factors, intrinsic properties of PG processivity provide a robust mechanism for cell straightening that is hardwired to the cell wall synthesis machinery. PMID:20479277

  14. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Benkowski, Robert J. (Inventor); Kiris, Cetin (Inventor); Kwak, Dochan (Inventor); Rosenbaum, Bernard J. (Inventor); Bacak, James W. (Inventor); DeBakey, Michael E. (Inventor)

    1999-01-01

    A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein.

  15. Colon unfolding via skeletal subspace deformation.

    PubMed

    Sudarsky, Sandra; Geiger, Bernhard; Chefd'hotel, Christophe; Guendel, Lutz

    2008-01-01

    We present an efficient method to digitally straighten a colon volume using mesh skinning, a technique well known in computer graphics to deform a polygonal mesh attached to a skeleton hierarchy. In our case, the colon centerline is used as the skeleton structure and the polyhedral model of the lumen as the skin that is to be deformed as the centerline is straightened. Once the colon has been straightened, we use standard rendering techniques to compute the virtual dissection. Our approach is significantly more efficient than previously proposed techniques.

  16. Effect of channel plane form on formation process of Sandbars

    NASA Astrophysics Data System (ADS)

    Takahashi, Gen; Yasuda, Hiroyasu

    Almost no explanation is given about development process of sand bar in non-straighten channel because the phenomenon of sand bar has been investigated using straighten channel. This study conducted a numerical experiment of development process of sand bar in a meandering channel and a figure-of-eight(gourd) as fixed wall. The results shows that the development process clearly differs in channel of straighten, meandering and figure-of-eight(gourd). The result of figure-of-eight(gourd) doesn't occur mode degradation and keep multiple bars.

  17. Treatment of the scoliotic nose with extracorporeal septoplasty.

    PubMed

    Gubisch, Wolfgang

    2015-02-01

    A septal deformity with severe deviation of the septal L strut is seen in nearly every crooked or scoliotic nose. Unless the underlying septal deformity is properly diagnosed and treated, the nasal axis cannot be completely straightened. In addition, because standard septoplasty techniques often fail to adequately address severe L-strut deformities, extracorporeal septoplasty is often a prerequisite for straightening the crooked nose. This article presents a detailed explanation of the extracorporeal technique, as well as representative long-term clinical results showing the efficacy and durability of extracorporeal septoplasty. Extracorporeal septoplasty a safe and reliable method for straightening the severely deviated nose.

  18. Rhinoplasty (Functional)

    MedlinePlus

    ... in the nasal breathing. Benefits An improvement in nasal airflow is the primary benefit of a rhinoplasty performed for functional reasons. The procedure may also straighten the nose, repair post-traumatic or congenital deformities, and improve ...

  19. Hair Treatments and Pregnancy

    MedlinePlus

    ... dyes. Common chemicals in hair dyes include hydrogen peroxide, ammonia, and alcohols. Hair curling or permanent wave ... thioglycolate and ammonia. Hair bleaching chemicals include hydrogen peroxide. Hair straighteners (relaxers) use a variety of chemicals. ...

  20. Braces Have Changed, From Metal to Tooth-Colored to Clear

    MedlinePlus

    ... for safety and effectiveness and, as appropriate, granting marketing authorization for the devices before they can be ... a little less. There really is no “faster” method of straightening teeth. Orthodontics work by applying slow ...

  1. Big Ben on a Shoestring.

    ERIC Educational Resources Information Center

    Kalotas, T. M.; Lee, A. R.

    1993-01-01

    This article describes a demonstration in which a straightened coathanger supported by threads and held near the ears resembles bells or gongs when struck. A mathematical explanation of the effect is provided. (MVL)

  2. 14 CFR Appendix A to Part 43 - Major Alterations, Major Repairs, and Preventive Maintenance

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... beams. (vii) Thin sheet webs of beams. (viii) Keel and chine members of boat hulls or floats. (ix... controllable pitch propellers. (xiii) Repairs to deep dents, cuts, scars, nicks, etc., and straightening of...

  3. 14 CFR Appendix A to Part 43 - Major Alterations, Major Repairs, and Preventive Maintenance

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Spar flanges. (vi) Members of truss-type beams. (vii) Thin sheet webs of beams. (viii) Keel and chine...) Repairs to deep dents, cuts, scars, nicks, etc., and straightening of aluminum blades. (xiv) The repair or...

  4. 14 CFR Appendix A to Part 43 - Major Alterations, Major Repairs, and Preventive Maintenance

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... beams. (vii) Thin sheet webs of beams. (viii) Keel and chine members of boat hulls or floats. (ix... controllable pitch propellers. (xiii) Repairs to deep dents, cuts, scars, nicks, etc., and straightening of...

  5. 14 CFR Appendix A to Part 43 - Major Alterations, Major Repairs, and Preventive Maintenance

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... beams. (vii) Thin sheet webs of beams. (viii) Keel and chine members of boat hulls or floats. (ix... controllable pitch propellers. (xiii) Repairs to deep dents, cuts, scars, nicks, etc., and straightening of...

  6. 14 CFR Appendix A to Part 43 - Major Alterations, Major Repairs, and Preventive Maintenance

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... beams. (vii) Thin sheet webs of beams. (viii) Keel and chine members of boat hulls or floats. (ix... controllable pitch propellers. (xiii) Repairs to deep dents, cuts, scars, nicks, etc., and straightening of...

  7. Scoliosis surgery - child

    MedlinePlus

    ... During surgery, your child's surgeon will use steel rods, hooks, screws, or other metal devices to straighten ... in to replace them. Metal instruments, such as rods, screws, hooks, or wires will also be placed ...

  8. Hair Treatments and Pregnancy

    MedlinePlus

    ... dyes. Common chemicals in hair dyes include hydrogen peroxide, ammonia, and alcohols. Hair curling or permanent wave ... thioglycolate and ammonia. Hair bleaching chemicals include hydrogen peroxide. Hair straighteners (relaxers) use a variety of chemicals. ...

  9. What Is Ankylosing Spondylitis?

    MedlinePlus

    ... joints. Omega-3 fatty acids, found in coldwater fish (such as tuna and salmon), flax seeds, and ... In very rare cases, surgery to straighten the spine may be recommended. This can only be done ...

  10. 16 CFR 301.9 - Use of terms “Mouton Lamb” and “Shearling Lamb” permitted.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... skin of a lamb which has been sheared, the hair straightened, chemically treated, and thermally set to produce a moisture repellant finish; as for example: Dyed Mouton Lamb (b) The term Shearling Lamb may be...

  11. 16 CFR 301.9 - Use of terms “Mouton Lamb” and “Shearling Lamb” permitted.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... skin of a lamb which has been sheared, the hair straightened, chemically treated, and thermally set to produce a moisture repellant finish; as for example: Dyed Mouton Lamb (b) The term Shearling Lamb may be...

  12. 16 CFR 301.9 - Use of terms “Mouton Lamb” and “Shearling Lamb” permitted.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... skin of a lamb which has been sheared, the hair straightened, chemically treated, and thermally set to produce a moisture repellant finish; as for example: Dyed Mouton Lamb (b) The term Shearling Lamb may be...

  13. 16 CFR 301.9 - Use of terms “Mouton Lamb” and “Shearling Lamb” permitted.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... skin of a lamb which has been sheared, the hair straightened, chemically treated, and thermally set to produce a moisture repellant finish; as for example: Dyed Mouton Lamb (b) The term Shearling Lamb may be...

  14. 16 CFR 301.9 - Use of terms “Mouton Lamb” and “Shearling Lamb” permitted.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... skin of a lamb which has been sheared, the hair straightened, chemically treated, and thermally set to produce a moisture repellant finish; as for example: Dyed Mouton Lamb (b) The term Shearling Lamb may be...

  15. 46 CFR 57.06-4 - Production testing specimen requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... pressure vessels as specified in § 57.06-5. (b) The test plates shall be so supported that the warping due... welding has warped the test plates, the plates shall be straightened before being stress-relieved....

  16. 46 CFR 57.06-4 - Production testing specimen requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... pressure vessels as specified in § 57.06-5. (b) The test plates shall be so supported that the warping due... welding has warped the test plates, the plates shall be straightened before being stress-relieved....

  17. 46 CFR 57.06-4 - Production testing specimen requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... pressure vessels as specified in § 57.06-5. (b) The test plates shall be so supported that the warping due... welding has warped the test plates, the plates shall be straightened before being stress-relieved....

  18. Braces

    MedlinePlus

    ... that straightens your teeth faster and easier. The rubber bands that go along with braces come in ... kids just need regular braces with wires and rubber bands doing their jobs to keep pressure on ...

  19. Problems with Legs and Feet

    MedlinePlus

    ... them by using stuff like special shoe inserts. Pigeon Toes Pigeon toes, or inwardly turning toes, is a common ... the other foot. Boys and girls both experience pigeon toes. Most kids' feet straighten naturally without any ...

  20. Transforming Discovery into Health | NIH MedlinePlus the Magazine

    MedlinePlus

    ... behavioral and social sciences research initiative. Shortening the Pathway to Health Whatever the disease, be it depression, ... opportunities for NIH to shorten and straighten the pathway from discovery to health. This expectation is grounded ...

  1. Big Ben on a Shoestring.

    ERIC Educational Resources Information Center

    Kalotas, T. M.; Lee, A. R.

    1993-01-01

    This article describes a demonstration in which a straightened coathanger supported by threads and held near the ears resembles bells or gongs when struck. A mathematical explanation of the effect is provided. (MVL)

  2. Cosmetic Dentistry

    MedlinePlus

    If you have stained, broken or uneven teeth, cosmetic dentistry can help. Cosmetic dentistry is different from orthodontic treatment, which can straighten your teeth with braces or other devices. Cosmetic dental procedures include Bleaching to make teeth whiter ...

  3. Tips for Taking Care of Your Limb

    MedlinePlus

    ... to straighten the knee). If you have a transfemoral (above-knee) amputation, do not sleep with: Your ... prosthesis; these may be a sign that the socket needs checking. If left untended, these red patches ...

  4. Precise Restraightening of Bent Studs

    NASA Technical Reports Server (NTRS)

    Boardman, R. E.

    1982-01-01

    Special tool quickly bends studs back into shape accurately and safely by force applied by hydraulic ram, with deflection being measured by dial indicator. Ram and indicator can be interchanged for straightening in reverse direction.

  5. 15. VIEW LOOKING SOUTHWEST INSIDE OF THE 22' BAR MILL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VIEW LOOKING SOUTHWEST INSIDE OF THE 22' BAR MILL SHIPPING BUILDING No. 1 AT THE 10' SUTTON BAR STRAIGHTENER. - U.S. Steel Duquesne Works, 22-Inch Bar Mill, Along Monongahela River, Duquesne, Allegheny County, PA

  6. Hand and Finger Exercises

    MedlinePlus

    ... each fingertip. Repeat ____ times for ____ seconds.  Bend the end joint of your finger, keeping the base and middle joints straight. Hold this position. Relax and then straighten the end joint. Hold this position. Repeat ____ times for ____ seconds.  ...

  7. Data Analysis in Cervical Trauma

    DTIC Science & Technology

    1989-04-01

    The cervical spine in lateral view is discussed and a method based on digital statistical analysis is used to reproduce quantitative data of the... cervical lordosis. (2) Marked straightening of the cervical spine. (3) Segmental straightening with reversal of the curve. Part II discusses the use of...the digital analysis to determine the displacement in subjects that have sustained ligamentous injuries of the cervical spine following whiplash injury.

  8. Autotropism, automorphogenesis, and gravity

    NASA Technical Reports Server (NTRS)

    Stankovic, B.; Volkmann, D.; Sack, F. D.

    1998-01-01

    Segments of organs that have undergone gravitropic curvature later straighten during the course of gravitropism or after the g-vector becomes randomized on a clinostat. Little is known about the mechanism underlying these and perhaps related phenomena which have been described with various overlapping terms such as autotropism, autotropic straightening, automorphosis, automorphogenesis, automorphic curvature, and gravitropic straightening. The types of phenomena that historically have been named by the above terms are reviewed critically with respect to an interaction with gravitropism. We suggest that the term "autotropism" should not be applied to the phenomenon of organ straightening that occurs during the course of gravitropism, since this straightening is part of a complex series of local growth adjustments overall through time, and since this phenomenon is not itself a tropistic response to a directional exogenous stimulus. It is suggested that the term autotropism should be used only for the phenomenon of organ straightening that occurs after the g-vector is randomized on a clinostat or withdrawn in the microgravity conditions of spaceflight. Usage of the term automorphogenesis is most appropriate for describing curvatures or orientations that result from morphological relationships such as in nastic curvatures.

  9. Autotropism, automorphogenesis, and gravity.

    PubMed

    Stankovic, B; Volkmann, D; Sack, F D

    1998-02-01

    Segments of organs that have undergone gravitropic curvature later straighten during the course of gravitropism or after the g-vector becomes randomized on a clinostat. Little is known about the mechanism underlying these and perhaps related phenomena which have been described with various overlapping terms such as autotropism, autotropic straightening, automorphosis, automorphogenesis, automorphic curvature, and gravitropic straightening. The types of phenomena that historically have been named by the above terms are reviewed critically with respect to an interaction with gravitropism. We suggest that the term "autotropism" should not be applied to the phenomenon of organ straightening that occurs during the course of gravitropism, since this straightening is part of a complex series of local growth adjustments overall through time, and since this phenomenon is not itself a tropistic response to a directional exogenous stimulus. It is suggested that the term autotropism should be used only for the phenomenon of organ straightening that occurs after the g-vector is randomized on a clinostat or withdrawn in the microgravity conditions of spaceflight. Usage of the term automorphogenesis is most appropriate for describing curvatures or orientations that result from morphological relationships such as in nastic curvatures.

  10. Autotropism, automorphogenesis, and gravity

    NASA Technical Reports Server (NTRS)

    Stankovic, B.; Volkmann, D.; Sack, F. D.

    1998-01-01

    Segments of organs that have undergone gravitropic curvature later straighten during the course of gravitropism or after the g-vector becomes randomized on a clinostat. Little is known about the mechanism underlying these and perhaps related phenomena which have been described with various overlapping terms such as autotropism, autotropic straightening, automorphosis, automorphogenesis, automorphic curvature, and gravitropic straightening. The types of phenomena that historically have been named by the above terms are reviewed critically with respect to an interaction with gravitropism. We suggest that the term "autotropism" should not be applied to the phenomenon of organ straightening that occurs during the course of gravitropism, since this straightening is part of a complex series of local growth adjustments overall through time, and since this phenomenon is not itself a tropistic response to a directional exogenous stimulus. It is suggested that the term autotropism should be used only for the phenomenon of organ straightening that occurs after the g-vector is randomized on a clinostat or withdrawn in the microgravity conditions of spaceflight. Usage of the term automorphogenesis is most appropriate for describing curvatures or orientations that result from morphological relationships such as in nastic curvatures.

  11. Comparison of hair shaft damage after chemical treatment in Asian, White European, and African hair.

    PubMed

    Lee, Yoonhee; Kim, Youn-Duk; Pi, Long-Quan; Lee, Sung Yul; Hong, Hannah; Lee, Won-Soo

    2014-09-01

    Diverse causes of extrinsic damage to the hair shaft have been documented and can be roughly divided into physical and chemical causes. Chemical causes of hair damage include bleaching, hair dyeing, and perming. The goal of this study was to investigate differences in patterns of serial damage in Asian, White European (WE), and African hair after chemical stress imposed by straightening and coloring treatments. Hairs were divided into control and treatment groups (straightening, coloring, and a combination of straightening and coloring). At 24 hours after the final treatment, patterns of hair damage were evaluated using transmission electron microscopy (TEM) and lipid TEM. Grades of hair cuticle and cortex damage were evaluated by three dermatologists. In the TEM examination, the cuticle of Asian hair proved to be resistant to damage caused by straightening treatments, whereas the WE hair cuticle and cortex were relatively susceptible to stress imposed by coloring treatments. In the combination treatment of straightening and coloring, African hair emerged as the most resistant to stress. In the lipid TEM examination, no notable differences in cell membrane complex damage were observed among the three groups of hairs. The present study suggests that WE hair is relatively susceptible and African hair is more resistant to chemical stresses, such as those imposed by straightening and coloring. © 2013 The International Society of Dermatology.

  12. Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants.

    PubMed

    Bastien, Renaud; Bohr, Tomas; Moulia, Bruno; Douady, Stéphane

    2013-01-08

    Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone auxin to the lower side is then enhanced, resulting in differential gene expression and cell elongation causing the organ to bend. However, little is known about the dynamics, regulation, and diversity of the entire bending and straightening process. Here, we modeled the bending and straightening of a rod-like organ and compared it with the gravitropism kinematics of different organs from 11 angiosperms. We show that gravitropic straightening shares common traits across species, organs, and orders of magnitude. The minimal dynamic model accounting for these traits is not the widely cited gravisensing law but one that also takes into account the sensing of local curvature, what we describe here as a graviproprioceptive law. In our model, the entire dynamics of the bending/straightening response is described by a single dimensionless "bending number" B that reflects the ratio between graviceptive and proprioceptive sensitivities. The parameter B defines both the final shape of the organ at equilibrium and the timing of curving and straightening. B can be estimated from simple experiments, and the model can then explain most of the diversity observed in experiments. Proprioceptive sensing is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies.

  13. Kinetics for phototropic curvature by etiolated seedlings of Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Orbovic, V.; Poff, K. L.

    1991-01-01

    An infrared-imaging system has been used to study the influence of gravity on the kinetics of first positive phototropism. The development of phototropic curvature of etiolated seedlings of Arabidopsis thaliana was measured in the absence of visible radiation. Following a pulse of blue light, stationary seedlings curved to a maximum of approximately 16 degrees about 80 minutes after stimulation. The seedlings then curved upward again or straightened by about 6 degrees during the subsequent 100 minutes. Seedlings rotated on a clinostat reached a similar maximum curvature following photostimulation. These seedlings maintained that curvature for 30 to 40 minutes before subsequently straightening to the same extent as the stationary seedlings. It is concluded that straightening is not a consequence of gravitropism, although gravity has some effect on the phototropism kinetics.

  14. Carpal valgus in llamas and alpacas: Retrospective evaluation of patient characteristics, radiographic features and outcomes following surgical treatment

    PubMed Central

    Hunter, Barbara; Duesterdieck-Zellmer, Katja F.; Huber, Michael J.; Parker, Jill E.; Semevolos, Stacy A.

    2014-01-01

    This study evaluated outcomes of surgical treatment for carpal valgus in New World camelids and correlated successful outcome (absence of carpal valgus determined by a veterinarian) with patient characteristics and radiographic features. Univariable and multivariable analyses of retrospective case data in 19 camelids (33 limbs) treated for carpal valgus between 1987 and 2010 revealed that procedures incorporating a distal radial transphyseal bridge were more likely (P = 0.03) to result in success after a single surgical procedure. A greater degree of angulation (> 19°, P = 0.02) and younger age at surgery (< 4 months, P = 0.03) were associated with unsuccessful outcome. Overall, 74% of limbs straightened, 15% overcorrected, and 11% had persistent valgus following surgical intervention. To straighten, 22% of limbs required multiple procedures, not including implant removal. According to owners, valgus returned following implant removal in 4 limbs that had straightened after surgery. PMID:25477542

  15. Developing processing techniques for Skylab data

    NASA Technical Reports Server (NTRS)

    Nalepka, R. F. (Principal Investigator); Malila, W. A.; Morgenstern, J. P.

    1975-01-01

    The author has identified the following significant results. The effects of misregistration and the scan-line-straightening algorithm on multispectral data were found to be: (1) there is greatly increased misregistration in scan-line-straightening data over conic data; (2) scanner caused misregistration between any pairs of channels may not be corrected for in scan-line-straightened data; and (3) this data will have few pure field center pixels than will conic data. A program SIMSIG was developed implementing the signature simulation model. Data processing stages of the experiment were carried out, and an analysis was made of the effects of spatial misregistration on field center classification accuracy. Fifteen signatures originally used for classifying the data were analyzed, showing the following breakdown: corn (4 signatures), trees (2), brush (1), grasses, weeds, etc. (5), bare soil (1), soybeans (1), and alfalfa (1).

  16. Management of Peyronie disease by implantation of inflatable penile prosthesis.

    PubMed

    Knoll, L D; Furlow, W L; Benson, R C

    1990-11-01

    Sixty-seven patients with advanced Peyronie disease were treated by implantation of an inflatable penile prosthesis (IPP). Twenty-eight of the 67 patients had documented total erectile failure. The remaining 39 patients had significant penile curvature causing "mechanical impotence" due to inability to achieve adequate vaginal penetration and chose implantation of an inflatable penile prosthesis (in some cases, combined with a straightening procedure) rather than one of the standard penile straightening procedures. Currently, 63 of the 67 patients have functioning prosthetic devices; in 3 other patients the device was removed because of infection, and 1 patient was dissatisfied and had the device removed. For impotent patients with severe Peyronie disease for whom other medical or surgical treatment is neither desirable nor suitable, we recommend implantation of an inflatable penile prosthesis combined with a possible straightening procedure.

  17. Kinetics for Phototropic Curvature by Etiolated Seedlings of Arabidopsis thaliana 1

    PubMed Central

    Orbović, Vladimir; Poff, Kenneth L.

    1991-01-01

    An infrared-imaging system has been used to study the influence of gravity on the kinetics of first positive phototropism. The development of phototropic curvature of etiolated seedlings of Arabidopsis thaliana was measured in the absence of visible radiation. Following a pulse of blue light, stationary seedlings curved to a maximum of approximately 16° about 80 minutes after stimulation. The seedlings then curved upward again or straightened by about 6° during the subsequent 100 minutes. Seedlings rotated on a clinostat reached a similar maximum curvature following photostimulation. These seedlings maintained that curvature for 30 to 40 minutes before subsequently straightening to the same extent as the stationary seedlings. It is concluded that straightening is not a consequence of gravitropism, although gravity has some effect on the phototropism kinetics. PMID:11538373

  18. Carpal valgus in llamas and alpacas: Retrospective evaluation of patient characteristics, radiographic features and outcomes following surgical treatment.

    PubMed

    Hunter, Barbara; Duesterdieck-Zellmer, Katja F; Huber, Michael J; Parker, Jill E; Semevolos, Stacy A

    2014-12-01

    This study evaluated outcomes of surgical treatment for carpal valgus in New World camelids and correlated successful outcome (absence of carpal valgus determined by a veterinarian) with patient characteristics and radiographic features. Univariable and multivariable analyses of retrospective case data in 19 camelids (33 limbs) treated for carpal valgus between 1987 and 2010 revealed that procedures incorporating a distal radial transphyseal bridge were more likely (P = 0.03) to result in success after a single surgical procedure. A greater degree of angulation (> 19°, P = 0.02) and younger age at surgery (< 4 months, P = 0.03) were associated with unsuccessful outcome. Overall, 74% of limbs straightened, 15% overcorrected, and 11% had persistent valgus following surgical intervention. To straighten, 22% of limbs required multiple procedures, not including implant removal. According to owners, valgus returned following implant removal in 4 limbs that had straightened after surgery.

  19. A Novel Representation for Riemannian Analysis of Elastic Curves in ℝn

    PubMed Central

    Joshi, Shantanu H.; Klassen, Eric; Srivastava, Anuj; Jermyn, Ian

    2011-01-01

    We propose a novel representation of continuous, closed curves in ℝn that is quite efficient for analyzing their shapes. We combine the strengths of two important ideas - elastic shape metric and path-straightening methods -in shape analysis and present a fast algorithm for finding geodesics in shape spaces. The elastic metric allows for optimal matching of features while path-straightening provides geodesics between curves. Efficiency results from the fact that the elastic metric becomes the simple 2 metric in the proposed representation. We present step-by-step algorithms for computing geodesics in this framework, and demonstrate them with 2-D as well as 3-D examples. PMID:21311729

  20. Taking Care of Your Hair

    MedlinePlus

    ... chemical treatments: Relaxers. Relaxers (straighteners) work by breaking chemical bonds in curly hair. Relaxers containing lye can cause skin irritation and hair breakage. Although "no lye" relaxers may cause less ... before a chemical relaxing treatment can increase these risks. And don' ...

  1. Influence of Physical Habitat and Agricultural Contaminants on Fishes within Agricultural Drainage Ditches

    USDA-ARS?s Scientific Manuscript database

    Agricultural drainage ditches are used within agricultural watersheds for the removal of excess water from agricultural fields. These headwater streams have been constructed or modified so they possess an enlarged trapezoidal cross-section, straightened channels, and riparian zones lacking woody veg...

  2. 40 CFR 63.5385 - How do I measure the quantity of finish applied to the leather?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) of this section: (i) Locate the flow sensor and other necessary equipment such as straightening vanes in or as close to a position that provides a representative flow. (ii) Use a flow sensor with a... distributions due to upstream and downstream disturbances. (iv) Conduct a flow sensor calibration check at...

  3. STS-34 Mission Specialist (MS) Chang-Diaz dons EMU during WETF exercises

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-34 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) Franklin R. Chang-Diaz dons extravehicular mobility unit (EMU) in preparation for an extravehicular activity (EVA) contingency exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. This closeup shows Chang-Diaz straightening his EMU sleeve.

  4. Analysis and Testing of a Tapered End Connection for Laser Welded Steel Sandwich Panels

    DTIC Science & Technology

    2009-08-15

    reduced distortion lessens or eliminates the need for straightening and rework . Cost-effective, and weight efficient designs are the result. As with...Structural Engineering Vol 67, pp. 159-166. 26. Vel, S.S., Caccese, V., Zhao.,H, 2005, Elastic coupling effects in tapered sandwich panels with laminated

  5. Bilingual Vocational Training Program. Auto Body Repair. Module 2.0: Tools and Equipment.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on tools and equipment is the second of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students…

  6. What If?--A Dream or Two About Teacher Education

    ERIC Educational Resources Information Center

    Welch, I. David

    1976-01-01

    A life-long teacher's kit should contain the following items: (1) a People Valuer, (2) a Self-Concept Conductor, (3) a Hook Straightener, (4) a Stereotype Stomper, (5) an Ignorance Eraser, (6) a Crap Detector, and (7) a Courage Booster. (MB)

  7. Bilingual Vocational Training Program. Auto Body Repair. Module 4.0: Auto Body Welding.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on auto body welding is the fourth of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students to…

  8. Braces

    MedlinePlus

    ... and they're made of a space-age material that straightens your teeth faster and easier. The rubber bands that go ... braces are removed and you can see your new and improved smile! Reviewed by: Steven Dowshen, MD Date reviewed: April ... Dentist Going to the Orthodontist Taking Care of Your Teeth Taking the Bite Out of Bruxism What's a ...

  9. Barber/Cosmetologist Curriculum. Program Information.

    ERIC Educational Resources Information Center

    Moraine Park Technical Coll., Fond du Lac, WI.

    This guide provides the instructor with materials for a barber/cosmetologist program. Seventeen study guides are provided: anatomy and physiology; applied chemistry; chemical straightening/relaxing; chemical waving; electricity and light therapy; facial services; hair coloring and lightening (bleach); hair cutting; hair, skin, and nail disorders;…

  10. Are Problems Prevalent and Stable in Non-Clinical Populations? Problems and Test-Retest Stability of a Patient-Generated Measure, PSYCHLOPS (Psychological Outcome Profiles), in a Non-Clinical Student Sample

    ERIC Educational Resources Information Center

    Evans, Chris; Ashworth, Mark; Peters, Marilyn

    2010-01-01

    In straightened times counselling must evidence the changes it promotes on reputable measures. Patient-generated measures complement nomothetic measures and may be nearer the ethos of counselling in eliciting individuals' problems. Scores from such measures from non-clinical samples are rarely reported, making their test-retest stability…

  11. Andy Wants to Be Grown Up: Managing Parental Anxiety.

    ERIC Educational Resources Information Center

    Hamilton, Jennifer

    1980-01-01

    The mother of a moderately retarded 11-year-old boy describes her reactions to having her son's teeth straightened. The author realized that the anxiety she felt about the orthodontic procedure was not so much concern for her son as her own fear of dental work. (PHR)

  12. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

    PubMed Central

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-01-01

    Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

  13. ESA MS Nicollier, assisted by technicians, dons EMU lower torso in JSC's WETF

    NASA Technical Reports Server (NTRS)

    1987-01-01

    European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier, seated and wearing a liquid cooling and ventilation garment (LCVG), pulls on the extravehicular mobility unit (EMU) lower torso as a technician straightens the EMU leg. Nicollier is preparing for an underwater extravehicular activity (EVA) simulation and familiarization session in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.

  14. Hair--Curvy or Straight; Cosmetology 1: 9205.04.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    Permanent curling and straightening require a thorough understanding of hair. Through diligent study and practice the student prepares for a profitable part of a beauty career. The course requires 135 hours of classroom-laboratory instruction. Those entering must have mastered the skills of shaping and conditioning hair. On completion of the…

  15. Automatic detection of plaques with severe stenosis in coronary vessels of CT angiography

    NASA Astrophysics Data System (ADS)

    Dinesh, M. S.; Devarakota, Pandu; Kumar, Jitendra

    2010-03-01

    Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of coronary arteries and is the leading cause of death worldwide. Computed tomography angiography (CTA) has been proved to be very useful for accurate noninvasive diagnosis and quantification of plaques. However, the existing methods to measure the stenosis in the plaques are not accurate enough in mid and distal segments where the vessels become narrower. To alleviate this, we propose a method that consists of three stages namely, automatic extraction of coronary vessels; vessels straightening; lumen extraction and stenosis evaluation. In the first stage, the coronary vessels are segmented using a parametric approach based on circular vessel model at each point on the centerline. It is assumed that centerline information is available in advance. Vessel straightening in the second stage performs multi-planar reformat (MPR) to straighten the curved vessels. MPR view of a vessel helps to visualize and measure the plaques better. On the straightened vessel, lumen and vessel wall are segregated using a nearest neighbor classification. To detect the plaques with severe stenosis in the vessel lumen, we propose a "Diameter Luminal Stenosis" method for analyzing the smaller segments of the vessel. Proposed measurement technique identifies the segments that have plaques and reports the top three severely stenosed segments. Proposed algorithm is applied on 24 coronary vessels belonging to multiple cases acquired from Sensation 64 - slice CT and initial results are promising.

  16. Scanning Electron Microscopy Study of Hair Shaft Damage Secondary to Cosmetic Treatments of the Hair

    PubMed Central

    Kaliyadan, Feroze; Gosai, BB; Al Melhim, Walid Naief; Feroze, Kaberi; Qureshi, Habib Ahmad; Ibrahim, Sayed; Kuruvilla, Joel

    2016-01-01

    Introduction and Background: Cosmetic procedures for hair, such as bleaching, dyeing, and straightening, are commonly used around the world. It has been suggested that excessive use of such procedures can cause damage to the hair shaft. We aimed to assess hair shaft changes using scanning electron microscopy (SEM) in female volunteers who frequently use hair treatment procedures such as bleaching, dyeing, or straightening. Methods: A cross-sectional, controlled study in a sample of 25 female volunteers (19 study group and 6 controls) in the age group of 18–45 years. The study group was composed of volunteers who regularly used different cosmetic hair treatment procedures such as bleaching, dyeing, and straightening (any one of these or a combination). The control group had never used any specific hair treatment procedure. The hair shaft damage as seen on SEM was assessed using a standardized scoring system and compared among the two groups statistically. The hair shafts were also examined clinically and with light microscopy. Results: No significant differences were seen between the test and control groups with regard to normal clinical examination and light microscopy findings. A higher degree of hair shaft damage was evident under SEM in the study group as compared to the control group. This difference was statistically significant. Conclusions: Regular use of procedures such as bleaching, dyeing, or straightening can lead to subtle changes in the hair shaft which can be detected early by SEM. PMID:27601867

  17. V-TECS Guide for Auto Body Repair.

    ERIC Educational Resources Information Center

    Gregory, Margaret R.; Benson, Robert T.

    This curriculum guide consists of materials for teaching a course in auto body repair. Addressed in the individual units of the guide are the following topics: the nature and scope of auto body repair; safety; tools; auto body construction; simple metal straightening; welding; painting and refinishing; refinishing complete lacquer; refinishing…

  18. 29 CFR 776.29 - Instrumentalities and channels of interstate commerce.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Instrumentalities and channels of interstate commerce. 776... Instrumentalities and channels of interstate commerce. (a) Typical examples. Instrumentalities and channels which... straightening routes or lines; providing cutoffs, tunnels, trestles, causeways, overpasses, underpasses...

  19. 77 FR 16207 - Stainless Steel Bar From Brazil, India, Japan, and Spain: Final Results of the Expedited Third...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    .... Stainless steel bar means articles of stainless steel in straight lengths that have been either hot-rolled, forged, turned, cold-drawn, cold-rolled or otherwise cold-finished, or ground, having a uniform solid... hot-rolled bar or from straightened and cut rod or wire, and reinforcing bars that have indentations...

  20. 49 CFR 572.85 - Lumbar spine flexure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Lumbar spine flexure. (a) When subjected to continuously applied force in accordance with paragraph (b... degrees at a force level of not less than 18 pounds and not more than 22 pounds, and straighten upon removal of the force to within 5 degrees of its initial position. (b) Test procedure. (1) The lumbar...

  1. Surgery for Peyronie's disease

    PubMed Central

    Levine, Laurence A; Larsen, Stephen M

    2013-01-01

    Peyronie's disease (PD) is most simply referred to as a fibrotic wound-healing disorder of the tunica albuginea. It is both a physically and psychologically devastating disorder that causes penile deformity, curvature, hinging, narrowing and shortening, which may compromise sexual function. Although a variety of non-surgical treatments have been suggested, none to date offer a reliable and effective correction of the penile deformity. As a result, surgery remains the gold standard treatment option, offering the most rapid and reliable treatment which will be the focus of this article. We review the preoperative evaluation, surgical algorithm, graft materials and postoperative management of PD. Outcomes for tunical shortening, tunical lengthening and penile prosthesis placement for penile straightening are reviewed. Tunica albuginea plication is the preferred method of straightening for men with adequate rigidity and less severe disease defined as curvature less than 70° without narrowing/hinging. Men who have more severe, complex deformity, but maintain strong preoperative erectile function should be considered candidates for straightening with plaque incision or partial excision and grafting. Finally, for those men who have inadequate rigidity and PD, penile prosthesis placement with straightening is the best approach to address both problems. PMID:23178395

  2. Tennis Rackets and the Parallel Axis Theorem

    ERIC Educational Resources Information Center

    Christie, Derek

    2014-01-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  3. An Introduction to Relaxed Hand Anthropometry

    DTIC Science & Technology

    Anthropometric data comparing the length of the relaxed hand with the flat, straightened hand are presented. The correlation coefficient between the hand length in the two positions is not high. A forthcoming comprehensive research program on the anthropometry of the hand is revealed.

  4. Andy Wants to Be Grown Up: Managing Parental Anxiety.

    ERIC Educational Resources Information Center

    Hamilton, Jennifer

    1980-01-01

    The mother of a moderately retarded 11-year-old boy describes her reactions to having her son's teeth straightened. The author realized that the anxiety she felt about the orthodontic procedure was not so much concern for her son as her own fear of dental work. (PHR)

  5. Bilingual Vocational Training Program. Auto Body Repair. Module 1.0: Beginning Auto Body.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on beginning auto body is the first of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students…

  6. Hot Forming With Electron-Beam Welder

    NASA Technical Reports Server (NTRS)

    Dobson, R. K.; Whiffen, E. L.

    1984-01-01

    Hot forming to restore size and shape of thin metal parts done with electron-beam welder. Work-piece heated in scanning defocused electron beam rather than conventional heat-treating furnace. Technique proved successful in straightening some thin flanges of nickel alloy and titanium.

  7. Bilingual Vocational Training Program. Auto Body Repair. Module 4.0: Auto Body Welding.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on auto body welding is the fourth of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students to…

  8. Nanostructure devices and fabrication method

    NASA Technical Reports Server (NTRS)

    Stevens, Ramsey M. (Inventor)

    2009-01-01

    An ion flux is directed to a carbon nanotube to permanently shape, straighten and/or bend the carbon nanotube into a desired configuration. Such carbon nanotubes have many properties that make them ideal as probes for Scanning Probe Microscopy and many other applications.

  9. Gravitropism and Autotropism in Cress Roots

    NASA Technical Reports Server (NTRS)

    Sack, Fred D.

    1998-01-01

    The overall purpose of this experiment was to study how cress roots respond to a withdrawal of a gravity stimulus i.e. when and how much the roots straighten (autotropism) after curving (gravitropism). This question was studied both in extensive ground-based research and in microgravity on BioRack.

  10. Flaunting It for Social Justice

    ERIC Educational Resources Information Center

    Jackson, Janna

    2010-01-01

    By examining various movements in education in "Flaunt It! Queers Organizing for Public Education and Justice," Quinn and Meiners show a systematic and intentional "straightening" of American public schools. Throughout the book, the authors explore how various public and private realms operate to try to silence queer voices, and they discuss ways…

  11. Scanning Electron Microscopy Study of Hair Shaft Damage Secondary to Cosmetic Treatments of the Hair.

    PubMed

    Kaliyadan, Feroze; Gosai, B B; Al Melhim, Walid Naief; Feroze, Kaberi; Qureshi, Habib Ahmad; Ibrahim, Sayed; Kuruvilla, Joel

    2016-01-01

    Cosmetic procedures for hair, such as bleaching, dyeing, and straightening, are commonly used around the world. It has been suggested that excessive use of such procedures can cause damage to the hair shaft. We aimed to assess hair shaft changes using scanning electron microscopy (SEM) in female volunteers who frequently use hair treatment procedures such as bleaching, dyeing, or straightening. A cross-sectional, controlled study in a sample of 25 female volunteers (19 study group and 6 controls) in the age group of 18-45 years. The study group was composed of volunteers who regularly used different cosmetic hair treatment procedures such as bleaching, dyeing, and straightening (any one of these or a combination). The control group had never used any specific hair treatment procedure. The hair shaft damage as seen on SEM was assessed using a standardized scoring system and compared among the two groups statistically. The hair shafts were also examined clinically and with light microscopy. No significant differences were seen between the test and control groups with regard to normal clinical examination and light microscopy findings. A higher degree of hair shaft damage was evident under SEM in the study group as compared to the control group. This difference was statistically significant. Regular use of procedures such as bleaching, dyeing, or straightening can lead to subtle changes in the hair shaft which can be detected early by SEM.

  12. Bilingual Vocational Training Program. Auto Body Repair. Module 2.0: Tools and Equipment.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on tools and equipment is the second of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students…

  13. Bilingual Skills Training Program. Auto Body Repair. Module 3.0: Basic Metal Repair.

    ERIC Educational Resources Information Center

    Northern New Mexico Community Coll., El Rito.

    This module on basic metal repair is the third of four (CE 028 303-306) in the auto body repair course of a bilingual vocational training program. The course is designed to furnish theoretical and laboratory experience in welding, metal straightening, metal finishing, painting, and use of power and hand tools. Module objectives are for students to…

  14. Speakeasy: A Text for Speaking, Volume 2. English for Special Purposes Series: Autobody Repair.

    ERIC Educational Resources Information Center

    Peet, William, Jr.

    This is the second of two volumes devoted to dialogs designed for classroom use by students of English as a second language. Survival skills are emphasized. The dialogs are grouped under the following titles: (1) "Buying Furniture," (2) "Straightening Metal Surfaces," (3) "Opening a Checking Account," (4) "Going…

  15. Tennis Rackets and the Parallel Axis Theorem

    ERIC Educational Resources Information Center

    Christie, Derek

    2014-01-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  16. Tennis Rackets and the Parallel Axis Theorem

    NASA Astrophysics Data System (ADS)

    Christie, Derek

    2014-04-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  17. Are Problems Prevalent and Stable in Non-Clinical Populations? Problems and Test-Retest Stability of a Patient-Generated Measure, PSYCHLOPS (Psychological Outcome Profiles), in a Non-Clinical Student Sample

    ERIC Educational Resources Information Center

    Evans, Chris; Ashworth, Mark; Peters, Marilyn

    2010-01-01

    In straightened times counselling must evidence the changes it promotes on reputable measures. Patient-generated measures complement nomothetic measures and may be nearer the ethos of counselling in eliciting individuals' problems. Scores from such measures from non-clinical samples are rarely reported, making their test-retest stability…

  18. Barber/Cosmetologist Curriculum. Program Information.

    ERIC Educational Resources Information Center

    Moraine Park Technical Coll., Fond du Lac, WI.

    This guide provides the instructor with materials for a barber/cosmetologist program. Seventeen study guides are provided: anatomy and physiology; applied chemistry; chemical straightening/relaxing; chemical waving; electricity and light therapy; facial services; hair coloring and lightening (bleach); hair cutting; hair, skin, and nail disorders;…

  19. 40 CFR 63.5385 - How do I measure the quantity of finish applied to the leather?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) of this section: (i) Locate the flow sensor and other necessary equipment such as straightening vanes in or as close to a position that provides a representative flow. (ii) Use a flow sensor with a... distributions due to upstream and downstream disturbances. (iv) Conduct a flow sensor calibration check at least...

  20. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography.

    PubMed

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-06-20

    Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

  1. View north of inside machine shop 36; shop floor accommodates ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View north of inside machine shop 36; shop floor accommodates lathes capable of machining a cylinder 60 inches in diameter and 75 feet long; other equipment includes horizontal and vertical jig borders, hydraulic tube straighteners and other equipment for precision machining of large ship components. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  2. 29 CFR 570.59 - Occupations involved in the operations of power-driven metal forming, punching, and shearing...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... metal forming, punching, and shearing machines (Order 8). 570.59 Section 570.59 Labor Regulations... involved in the operations of power-driven metal forming, punching, and shearing machines (Order 8). Link..., and shearing machines: (i) All rolling machines, such as beading, straightening, corrugating,...

  3. Flaunting It for Social Justice

    ERIC Educational Resources Information Center

    Jackson, Janna

    2010-01-01

    By examining various movements in education in "Flaunt It! Queers Organizing for Public Education and Justice," Quinn and Meiners show a systematic and intentional "straightening" of American public schools. Throughout the book, the authors explore how various public and private realms operate to try to silence queer voices, and they discuss ways…

  4. Gravitropism and phototropism of oat coleoptiles: post-tropic autostraightening and tissue shrinkage during tropism.

    PubMed

    Tarui, Y; Iino, M

    1999-01-01

    We measured changes in length on the two opposite sides of the red-light-grown oat (Avena sativa L.) coleoptiles subjected to either gravitropic or phototropic stimulation and subsequently rotated on a horizontal clinostat. The length measurement was conducted using three 5 mm-long zones delimited by ink markers from the tip. Curvature of each zone was analyzed from the length difference between the two sides. Gravitropism was induced by displacing the seedling from the vertical by 30 degrees or 90 degrees for 25 min. Phototropism was induced by exposing the coleoptile to unilateral blue light for 30 s, which provided a fluence (1.0 micromoles m-2) optimal for the pulse-induced positive phototropism or a lower, suboptimal fluence (0.03 micromoles m-2). After negatively gravitropic bending, the upper two zones straightened rapidly at either displacement angle. After positively phototropic bending, straightening occurred, but only in the top zone and at the lower fluence. The upper two zones straightened rapidly, however, when bilateral blue light (30 s; 15 micromoles m-2 from either direction) was applied 25 min after unilateral stimulation at the higher fluence. Bilateral blue light alone induced no curvature. These results confirm that the straightening of gravitropically bent coleoptiles is autonomic, and suggest that a similar autonomic response participates in the straightening of phototropically bent coleoptiles. Suppression of elongation on the concave side of the coleoptile mainly accounted for gravitropic and phototropic curvatures. The concave side of the top zone shrank during both tropisms. This shrinkage progressed at a high rate from the beginning of curvature response, suggesting that a drop in turgor pressure is the main and direct cause of the shrinkage.

  5. Optic Nerve Sheath as a Novel Mechanical Load on the Globe in Ocular Duction

    PubMed Central

    Demer, Joseph L.

    2016-01-01

    Purpose The optic nerve (ON) sheath's role in limiting duction has been previously unappreciated. This study employed magnetic resonance imaging (MRI) to demonstrate this constraint on adduction. Methods High-resolution, surface coil axial MRI was obtained in 11 normal adults, 14 subjects with esotropia (ET) having normal axial length (AL) < 25.8 mm, 13 myopic subjects with ET and mean AL 29.3 ± 3.3 (SD) mm, and 7 subjects with exotropia (XT). Gaze angles and ON lengths were measured for scans employing eccentric lateral fixation in which an ON became completely straightened. Results In all groups, ON straightening occurred only in the adducting, not abducting, eye. Adduction at ON straightening was 26.0 ± 8.8° in normal subjects, not significantly different from XT at 22.2 ± 11.8°. However, there was significant increase in comparable adduction in ET to 36.3 ± 9.3°, and in myopic ET to 33.6 ± 10.7° (P < 0.04). Optic nerve length at straightening was 27.6 ± 2.7 mm in normals, not significantly different from 28.2 ± 2.8 mm in ET and 27.8 ± 2.7 mm in XT. In myopic ET, ON length at straightening was significantly reduced to 24.0 ± 2.9 mm (P < 0.002) and was associated with globe retraction in adduction, suggesting ON tethering. Conclusions Large adduction may exhaust length redundancy in the normally sinuous ON and sheath, so that additional adduction must stretch the sheath and retract or deform the globe. These mechanical effects are most significant in ET with axial myopia, but may also exert traction on the posterior sclera absent strabismus or myopia. Tethering by the ON sheath in adduction is an important, novel mechanical load on the globe. PMID:27082297

  6. Investigation of healthcare-acquired infections associated with Pseudomonas aeruginosa biofilms in taps in neonatal units in Northern Ireland.

    PubMed

    Walker, J T; Jhutty, A; Parks, S; Willis, C; Copley, V; Turton, J F; Hoffman, P N; Bennett, A M

    2014-01-01

    In December 2011 and early 2012 four neonates died from Pseudomonas aeruginosa bacteraemia in hospitals in Northern Ireland. To assess whether P. aeruginosa was associated with the neonatal unit taps and whether waterborne isolates were consistent with patient isolates. Thirty taps and eight flow straighteners from the relevant hospitals were categorized and dismantled into 494 components and assessed for aerobic colony and P. aeruginosa counts using non-selective and selective agars. P. aeruginosa isolates were typed by variable number tandem repeat (VNTR) analysis. Selected tap components were subjected to epifluorescence and scanning electron microscopy to visualize biofilm. The highest P. aeruginosa counts were from the flow straighteners, metal support collars and the tap bodies surrounding these two components. Complex flow straighteners had a significantly higher P. aeruginosa count than other types of flow straighteners (P < 0.05). Highest aerobic colony counts were associated with integrated mixers and solenoids (P < 0.05), but there was not a strong correlation (r = 0.33) between the aerobic colony counts and P. aeruginosa counts. Representative P. aeruginosa tap isolates from two hospital neonatal units had VNTR profiles consistent with strains from the tap water and infected neonates. P. aeruginosa was predominantly found in biofilms in flow straighteners and associated components in the tap outlets and was a possible source of the infections observed. Healthcare providers should be aware that water outlets can be a source of P. aeruginosa contamination and should take steps to reduce such contamination, monitor it and have strategies to minimize risk to susceptible patients. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  7. Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants

    PubMed Central

    Bastien, Renaud; Bohr, Tomas; Moulia, Bruno; Douady, Stéphane

    2013-01-01

    Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone auxin to the lower side is then enhanced, resulting in differential gene expression and cell elongation causing the organ to bend. However, little is known about the dynamics, regulation, and diversity of the entire bending and straightening process. Here, we modeled the bending and straightening of a rod-like organ and compared it with the gravitropism kinematics of different organs from 11 angiosperms. We show that gravitropic straightening shares common traits across species, organs, and orders of magnitude. The minimal dynamic model accounting for these traits is not the widely cited gravisensing law but one that also takes into account the sensing of local curvature, what we describe here as a graviproprioceptive law. In our model, the entire dynamics of the bending/straightening response is described by a single dimensionless “bending number” B that reflects the ratio between graviceptive and proprioceptive sensitivities. The parameter B defines both the final shape of the organ at equilibrium and the timing of curving and straightening. B can be estimated from simple experiments, and the model can then explain most of the diversity observed in experiments. Proprioceptive sensing is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies. PMID:23236182

  8. Streambed adjustment and channel widening in eastern Nebraska

    USGS Publications Warehouse

    Rus, David L.; Dietsch, Benjamin J.; Simon, Andrew

    2003-01-01

    In eastern Nebraska, stream straightening and dredging efforts since the 1890s have disturbed the natural equilibrium of stream channels and have led to streambed adjustment by degradation and subsequent channel widening. This report describes a study to evaluate the effect these disturbances have had on stream channels in eastern Nebraska. Two sets of survey data were collected approximately 2 years apart during 1996-99 at 151 primary sites. Additionally, historical streambed-elevation data (dating back to the 1890s) were compiled from several sources for the primary sites and 45 supplemental sites, and relevant disturbances were identified for each of eight basin groupings. Streambed-elevation data sets were used to estimate the amount of change to the streambed at the sites over the time period of the data. Recent channel widening was documented for 73 of the primary sites by comparing the two survey sets. The majority of observed streambed-gradation responses appear to be related to the various straightening efforts and to the effects of grade-control structures in the study area. Channel responses were complicated by the presence of multiple disturbances. However, in many cases, the streambed-elevation data sets provide a reliable representation of the past streambed gradation, with some sites showing 6 to 7 meters of degradation since they were straightened. Many sites that had been straightened showed considerable degradation following the disturbance. This indicates that eastern Nebraska stream channels can regain equilibrium mainly through the slope adjustment process of head-ward-progressing degradation. Bank failures were documented at sites in all eight of the basin groupings analyzed, and widening rates were computed at 64 of 73 sites. Observed bank widening in the Big Blue River Basin, a relatively unstraightened basin, indicates that other disturbances besides stream-channel straightening may be causing channel responses in the basin and possibly in

  9. Gravitropism and phototropism of oat coleoptiles: Post-tropic autostraightening and tissue shrinkage during tropism

    NASA Astrophysics Data System (ADS)

    Tarui, Y.; Iino, M.

    1999-01-01

    We measured changes in length on the two opposite sides of the red-light-grown oat (Avena sativa L.) coleoptiles subjected to either gravitropic or phototropic stimulation and subsequently rotated on a horizontal clinostat. The length measurement was conducted using three 5 mm-long zones delimited by ink markers from the tip. Curvature of each zone was analyzed from the length difference between the two sides. Gravitropism was induced by displacing the seedling from the vertical by 30° or 90° for 25 min. Phototropism was induced by exposing the coleoptile to unilateral blue light for 30 s, which provided a fluence (1.0 μmol m-2) optimal for the pulse-induced positive phototropism or a lower, suboptimal fluence (0.03 μmol m-2). After negatively gravitropic bending, the upper two zones straightened rapidly at either displacement angle. After positively phototropic bending, straightening occurred, but only in the top zone and at the lower fluence. The upper two zones straightened rapidly, however, when bilateral blue light (30 s; 15 μmol m-2 from either direction) was applied 25 min after unilateral stimulation at the higher fluence. Bilateral blue light alone induced no curvature. These results confirm that the straightening of gravitropically bent coleoptiles is autonomic, and suggest that a similar autonomic response participates in the straightening of phototropically bent coleoptiles. Suppression of elongation on the concave side of the coleoptile mainly accounted for gravitropic and phototropic curvatures. The concave side of the top zone shrank during both tropisms. This shrinkage progressed at a high rate from the beginning of curvature response, suggesting that a drop in turgor pressure is the main and direct cause of the shrinkage.

  10. Inward spread of activation in vertebrate muscle fibres

    PubMed Central

    González-Serratos, H.

    1971-01-01

    1. A method for detecting the activation of individual myofibrils or groups of myofibrils within an isolated muscle fibre is described. It consists in making all the myofibrils wavy by setting the fibre in gelatine and compressing it longitudinally; active shortening of myofibrils can then be recognized by the straightening out of the waves. 2. The time course of this straightening during a twitch was found by high-speed ciné micrography. 3. There is a delay of activation between the superficial and central myofibrils, from which the velocity of inward spread of activation can be found. 4. This velocity has a Q10 of 2, and is about 7 cm/sec at 20° C. The mechanism of the inward spread of activation is discussed. 5. On relaxation the waves reappear, showing that there is a spontaneous elongation of the myofibrils. ImagesPlate 1Plate 2Plate 3Plate 4 PMID:5557071

  11. The use of skeletal extension torque in reversing Dupuytren contractures of the proximal interphalangeal joint.

    PubMed

    Agee, John M; Goss, Ben C

    2012-07-01

    Dupuytren contracture of the proximal interphalangeal (PIP) joint can be reversed by an extension torque transmitted from an external device, the Digit Widget, by skeletal pins to the middle phalanx. This extension torque, generated by the same elastic bands dentists use to align teeth, gradually restores length to soft tissues palmar to the PIP joint's axis of rotation. Simultaneously, tissues dorsal to the joint's axis will shorten toward normal length as the PIP progressively straightens. Although the contractile nodules and bands of Dupuytren disease may be excised either before or after reversal of the joint's contracture, a 2-staged approach is preferred: (1) reverse the PIP flexion contracture, and (2) excise the diseased tissue from the straightened finger. We believe this 2-staged approach yields better results. In addition, it is technically easier to avoid injury to nerves and arteries while excising the nodules and bands, when one operates through palmar skin of more nearly normal length.

  12. Growth distribution during phototropism of Arabidopsis thaliana seedlings

    SciTech Connect

    Orbovic, V.; Poff, K.L. )

    1993-09-01

    The elongation rates of two opposite sides of hypocotyls of Arabidopsis thaliana seedlings were measured during phototropism by using an infrared imaging system. In first positive phototropism, second positive phototropism, and red light-enhanced first positive phototropism, curvature toward the light source was the result of an increase in the rate of elongation of the shaded side and a decrease in the rate of elongation of the lighted side of the seedlings. The phase of straightening that followed maximum curvature resulted from a decrease in the elongation rate of the shaded side and an increase in the elongation rate of the lighted side. These data for the three types of blue light-induced phototropism tested in this study and for the phase of straightening are all clearly consistent with the growth rate changes predicted by the Cholodny-Went theory. 31 refs., 7 figs.

  13. Application of CFD to Explain Anomalous Stall Behavior of the SSME Flowmeter

    NASA Technical Reports Server (NTRS)

    Ascoli, E.; Clever, W.; Hadid, A.; Lynch, E. D.; Stewart, M.; Lee, K.

    1999-01-01

    The Space Shuttle Main Engine (SSME) Fuel Flowmeter is located in the duct between the low and high pressure fuel turbopumps. In the flowmeter the rotation rate of a 4-blade rotor positioned downstream of two flow straighteners is employed to measure the engine fuel flow rate and thereby control the engine mixture ratio via the engine controller. Hence, inaccurate operation of the flowmeter could have serious consequences for SSME engine operation and performance, forcing, for example, tanking of extra fuel to allow for inaccurate flowmeter measurement. Since the current flight flowmeter configuration was incorporated into the SSME in the early eighties, some anomalies in flowmeter behavior have been observed. The initial flowmeter incorporated an "egg crate" design for the two flow straighteners which turn the duct flow to make it more uniform and parallel after it has come out of the 90 degree bend just upstream of the flowmeter.

  14. The aerodynamic performance of several flow control devices for internal flow systems

    NASA Technical Reports Server (NTRS)

    Eckert, W. T.; Wettlaufer, B. M.; Mort, K. W.

    1982-01-01

    An experimental reseach and development program was undertaken to develop and document new flow-control devices for use in the major modifications to the 40 by 80 Foot wind tunnel at Ames Research Center. These devices, which are applicable to other facilities as well, included grid-type and quasi-two-dimensional flow straighteners, louver panels for valving, and turning-vane cascades with net turning angles from 0 deg to 90 deg. The tests were conducted at model scale over a Reynolds number range from 2 x 100,000 to 17 x 100,000, based on chord. The results showed quantitatively the performance benefits of faired, low-blockage, smooth-surface straightener systems, and the advantages of curved turning-vanes with hinge-line gaps sealed and a preferred chord-to-gap ratio between 2.5 and 3.0 for 45 deg or 90 deg turns.

  15. ORTHOPEDIC LEG BRACE

    NASA Technical Reports Server (NTRS)

    Myers, William Neil (Inventor)

    2005-01-01

    Knee braces generally have been rigid in both the knee bending direction and in the knee straightening direction unless a manually operated release is incorporated in them to allow the knee to bend. Desirably a braced knee joint should effectively duplicate the compound, complex, actions of a normal knee. The key to knee braces is the knee joint housing. The housing herein carries a number of cam action pawls. with teeth adapted to engage the internal teeth of a ratchet ring mounted in the housing. Cam action return springs and the shape of the cam action pawl teeth allow rotation of the ratchet ring in a leg straightening direction while still supporting a load. The leg can then be extended during walking while at the same time being prevented by the cam action pawls from buckling in the knee bending direction.

  16. Ten pearls every dermatologist should know about the appropriate use of relaxers.

    PubMed

    Richardson, Vanessa; Agidi, Ada T; Eaddy, Erica R; Davis, Loretta S

    2017-03-01

    Chemical relaxers are products marketed to straighten the hair and have been principally used by African Americans since the early twentieth century. They contain alkaline agents that break and reform hydrogen and disulfide bonds, leaving hair permanently straightened. Relaxers cause loss of tensile strength and increased fragility of the hair shaft that lead to increased risk of hair breakage and thinning. When used improperly, they can also cause local irritant contact dermatitis and chemical burns to the scalp and hairline that can potentially lead to a scarring alopecia. After interviewing several cosmetology educators in the field and reviewing the literature, we generated a list of ten pearls that all dermatologists should know about relaxers to provide professional guidance to their patients. © 2016 Wiley Periodicals, Inc.

  17. Straight hole driller

    SciTech Connect

    Samford, T.L.

    1981-08-25

    For use in a drilling string, the preferred and illustrated embodiment depicts a drill collar to be placed in the lower parts of the drill string for straightening the hole. The preferred embodiment utilizes a generally square drill collar with a thick or heavy wall. It is square in cross section along the greater portion of its length, the four corners being slightly rounded to a specified diameter on rotation, and the four lengthwise corners of the regular cross section are all reinforced with hardfacing material to a specified depth, typically tungsten carbide. The four edges abrade the bore hole as the drill string penetrates the earth. In addition, the lower end of the tubular body includes lengthwise flutes in the form known on a stabilizer to guide the hole straightening device into the hole to be reamed by operation of the device.

  18. Bending Distortion Analysis of a Steel Shaft Manufacturing Chain from Cold Drawing to Grinding

    NASA Astrophysics Data System (ADS)

    Dias, Vinicius Waechter; da Silva Rocha, Alexandre; Zottis, Juliana; Dong, Juan; Epp, Jérémy; Zoch, Hans Werner

    2017-01-01

    Shafts are usually manufactured from bars that are cold drawn, cut machined, induction hardened, straightened, and finally ground. The main distortion is characterized by bending that appears after induction hardening and is corrected by straightening and/or grinding. In this work, the consequence of the variation of manufacturing parameters on the distortion was analyzed for a complete manufacturing route for production of induction hardened shafts made of Grade 1045 steel. A DoE plan was implemented varying the drawing angle, cutting method, induction hardening layer depth, and grinding penetration depth. The distortion was determined by calculating curvature vectors from dimensional analysis by 3D coordinate measurements. Optical microscopy, microhardness testing, residual stress analysis, and FEM process simulation were used to evaluate and understand effects of the main carriers of distortion potential. The drawing process was identified as the most significant influence on the final distortion of the shafts.

  19. Axial Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  20. Clinical and anthropological perspectives on chemical relaxing of afro-textured hair.

    PubMed

    Aryiku, S A; Salam, A; Dadzie, O E; Jablonski, N G

    2015-09-01

    The culturally engrained practice of 'relaxing' afro-textured hair has been linked with hair and scalp disorders. Herein, we discuss the evolution of human hair types, focusing in particular on afro-textured hair. We explore the biological features of this hair type, and discuss the different methods employed to straighten afro-textured hair, focusing in particular on chemical straightening. We also examine clinical, anthropological, and psychological issues associated with this latter practice. Examples of common scalp pathologies associated with chronic hair relaxing, such as alopecia, hair breakage, caustic burns and irritant contact dermatitis, are also highlighted. The data presented herein should enable clinicians to engage in culturally appropriate discussions with their patients about issues of appearance and conformity.

  1. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J. (Inventor); Akkerman, James W. (Inventor); Aber, Greg S. (Inventor); Vandamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1993-01-01

    A rotary blood pump is presented. The pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial, and radial clearances of the blades associated with the flow straightener, inducer portion, impeller portion, and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with crosslinked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  2. Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1996-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  3. Bending Distortion Analysis of a Steel Shaft Manufacturing Chain from Cold Drawing to Grinding

    NASA Astrophysics Data System (ADS)

    Dias, Vinicius Waechter; da Silva Rocha, Alexandre; Zottis, Juliana; Dong, Juan; Epp, Jérémy; Zoch, Hans Werner

    2017-04-01

    Shafts are usually manufactured from bars that are cold drawn, cut machined, induction hardened, straightened, and finally ground. The main distortion is characterized by bending that appears after induction hardening and is corrected by straightening and/or grinding. In this work, the consequence of the variation of manufacturing parameters on the distortion was analyzed for a complete manufacturing route for production of induction hardened shafts made of Grade 1045 steel. A DoE plan was implemented varying the drawing angle, cutting method, induction hardening layer depth, and grinding penetration depth. The distortion was determined by calculating curvature vectors from dimensional analysis by 3D coordinate measurements. Optical microscopy, microhardness testing, residual stress analysis, and FEM process simulation were used to evaluate and understand effects of the main carriers of distortion potential. The drawing process was identified as the most significant influence on the final distortion of the shafts.

  4. Stream Channel Stability. Appendix D. Bank Stability and Bank Material Properties in the Bluffline Streams of Northwest Mississippi,

    DTIC Science & Technology

    1981-04-01

    2.5 Pulling Assembly, Base Plate and Gas Control Console ....... . 197 2.6 Pulling force is applied by cranking the handle at a rate of two turns per...last fifty years. This degradation is the result of changes in land use, channel straightening and lowering of effective base level by trunk stream... overfall . This headcut forms where the channel bed breaks through resistant substrata of ironstone or clay. The streams lack any bedrock control and are

  5. Minimally invasive veneers: current state of the art

    PubMed Central

    Vanlıoğlu, Burçin Akoğlu; Kulak-Özkan, Yasemin

    2014-01-01

    Ceramic veneers are considered a conservative solution for patients requiring improvement of the shape, color, or position of their anterior teeth. Ceramic veneers have been extensively and successfully used to mask intrinsic staining, to give the appearance of straightening, and to correct minor malformations of anterior teeth without the removal of substantial amounts of sound tooth substance. The current literature was reviewed to search for the most important parameters determining the long-term success and correct application of ceramic veneers. PMID:25506248

  6. Hamiltonian formalism in the equilibrium problem for a plasma with islands

    SciTech Connect

    Skovoroda, A. A.

    2011-08-15

    Hamiltonian formalism is applied to the equilibrium problem for a plasma with islands by using an analogy between the equilibrium problem for a plasma with one island and the nonlinear mechanics of a physical pendulum. A relationship is established between magnetic flux coordinates with straightened magnetic field lines and the action-angle variables. The flux and current representations of a magnetic field with islands are obtained, and the solution to the equilibrium problem for a narrow island is presented.

  7. Iliac artery occlusion with "oxbow lake" formation following stent deployment in a tortuous external iliac artery during EVAR: a case report.

    PubMed

    Culverwell, Adam D; Kent, Patrick; Puppala, Sapna

    2011-10-01

    In this case report, we describe a complication that we term the "oxbow lake" deformity. This phenomenon occurs when a tortuous elongated external iliac artery segment is artificially straightened by an iliac stent resulting in kinking and compression of a redundant loop with lumen compromise. We describe the anatomy, corrective treatment, and outcome. This occurrence is potentially foreseeable with tortuous vascular anatomy and recognition can allow appropriate management planning avoiding complications for the patient.

  8. Review Plan Using the NWD Model Review Plan for Continuing Authorities Program Section 14, 107, 111, 204, 206, 208, 1135 and Projects Directed by Guidance to Use CAP Procedures: Sheridan, Wyoming, Section 1135 Project

    DTIC Science & Technology

    2014-12-19

    flood discharges in Goose and Little Goose Creeks. Construction of the Sheridan Project was completed in two stages. Stage 1 was started in August...construction and channel straightening on Little Goose Creek upstream from Stage 1 construction. Construction of Stage 2 was completed in 1966. According...to the Operations and Maintenance Manual for the project there was a proposed Stage 3 involving construction upstream on Big Goose Creek that was

  9. Experimental Investigation of a Supersonic Turbulent Boundary Layer with Adverse Pressure Gradient

    DTIC Science & Technology

    1995-12-01

    gaseous flow. Seed particles, such as smoke, latex spheres, or olive oil , are introduced into the flow field. As these particles pass through the...Straightener O Seed From Atomizer Figure 4-8: Six-jet Atomizer and Injector Schematic The seed particles were generated by passing 100% pure olive oil through...between flow properties and the number of 4-11 jets existed; the flow rate doubled when two jets were used. The diameter of the olive oil particles was

  10. [Correction of posture disorders and scoliosis in schoolchildren using functional biofeedback].

    PubMed

    Bogdanov, O V; Nikolaeva, N I; Mikhaĭlenok, E L

    1990-01-01

    A novel technique is offered for correction of postural defects and early manifestations of scoliosis in schoolchildren using methods of functional biofeedback training. The technique allowed the patient to use the biofeedback signals informing on the degree of asymmetry in bioelectric activity of paravertebral muscles in static active straightening of the vertebral column. The data revealed a steady decrease in asymmetric activity indices in muscles erecting the column. This provided a physiological basis for a high clinical efficiency of the technique.

  11. Analysis of data on absorption in the northern part of the milky way

    NASA Technical Reports Server (NTRS)

    Polishchuk, E. P.

    1973-01-01

    The values of absorption for different galactic longitudes are obtained on the basis of star cluster data. It is found that the distance up to the point, where the straightening of the absorption distribution curve begins, depends on the limiting magnitude of the catalogue and the density of absorbing matter near the sun. The picture of absorbing matter distribution in the northern part of the Milky Way is given.

  12. SPRING DRIVEN ACTUATING MECHANISM FOR NUCLEAR REACTOR CONTROL

    DOEpatents

    Bevilacqua, F.; Uecker, D.F.; Groh, E.F.

    1962-01-23

    l962. rod in a nuclear reactor to shut it down. The control rod or an extension thereof is wound on a drum as it is withdrawn from the reactor. When an emergency occurs requiring the reactor to be shut down, the drum is released so as to be free to rotate, and the tendency of the control rod or its extension coiled on the drum to straighten itself is used for quickly returning the control rod to the reactor. (AEC)

  13. Preliminary Material Properties Handbook. Volume 2: SI Units

    DTIC Science & Technology

    2007-11-02

    3-35 3.7.3.0(b) Typical Mechanical and Physical Properties of 7249-T76511 Aluminum Alloy Extruded Bars, Rods, Shapes, and Tubing ...Ring Forgings and Rolled Rings .... 1 to 5% permanent set. T_510 Applies to extruded rod, bar, shapes and tube and to drawn tube when stretched the...straightening after stretching. Extruded Rod, Bar, Shapes and Tube .... 1 to 3% permanent set. Drawn Tube .... ½ to 3% permanent set. T_511 Applies to

  14. STS-32 MS Dunbar dons EMU upper torso prior to WETF exercises

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-32 Mission Specialist (MS) Bonnie J. Dunbar, standing on platform, holds her arms out while technicians straighten and adjust extravehicular mobility unit (EMU) upper torso sleeves. Dunbar smiles as the communications carrier assembly (CAA) dangles from the EMU neck ring. The EMU suiting is in preparation for a session of underwater training in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Once suited, Dunbar will participate in a contingency extravehicular activity (EVA) simulation in the nearby 25 ft deep pool.

  15. [Application of mind map in teaching of medical parasitology].

    PubMed

    Zhou, Hong-Chang; Shao, Sheng-Wen; Xu, Bo-Ying

    2012-12-30

    To improve the teaching quality of medical parasitology, mind map, a simple and effective learning method, was introduced. The mind map of each chapter was drawn by teacher and distributed to students before the class. It was helpful for teacher to straighten out the teaching idea, and for students to grasp the important learning points, perfect the class notes and improve learning efficiency. The divergent characteristics of mind map can also help to develop the students' innovation ability.

  16. Transnasal Endoscope Locked in a Bent Position Causing Difficult Withdrawal

    PubMed Central

    Kumada, Takashi; Hisanaga, Yasuhiro

    2014-01-01

    We report a rare but severe complication of routine transnasal esophagogastroduodenoscopy (EGD). The tip of a transnasal endoscope was locked in a bent position. Since the bent tip was unable to be returned to a neutral position, the snare from another endoscope inserted transorally was used to straighten it, which allowed the transnasal endoscope to be withdrawn with only mild injury to the gastric mucosa. Endoscopists should be aware of this complication and how to manage it. PMID:26157831

  17. Transient Plasma Ignition for Small Internal Combustion Engines

    DTIC Science & Technology

    2013-02-01

    engines having large combustion chamber surface area to volume ratios. Piston and cylinder head design, intake manifold flow straighteners, and...Combustion Engines FA9550-10-1-0554 Dr. Martin A. Gundersen Dr. Paul Ronney University of Southern California Department of Contracts & Grants 3720 S...focused on introducing transient plasma ignition (TPI) into a small combustion engine (2 hp Fuji Imvac BF-34EI), seeking to demonstrate improved

  18. French Plans for Fifth Generation Computer Systems.

    DTIC Science & Technology

    1984-12-07

    described as follows: assume a account coupling and nonlinearities by target that can be gripped and a grasp- using a dynamic model of the manipula... pincers to permit centering, straighten- torques. One approach is to precompen- ing, and movement. An observation site, sate for nonlinear terms using a...motions. However, for large sponding to a Newtonian potential, and and fast motions a linear model of the continuity with gripping is assured by joint

  19. [Hypospadias and its treatment].

    PubMed

    Paye-Jaouen, Annabel

    2013-01-01

    Hypospadias is a malformation of the penis which can be benign or severe. Surgical treatment is carried out from the age of 9 months, in order to straighten the penis, reconstruct the urethra and the glans and to secure skin cover.These children need to be followed-up until puberty, in order to prevent complications and to put in place any necessary psychosocial support.

  20. Update on medical management of Peyronie's disease.

    PubMed

    Tan, Ronny B W; Sangkum, Premsant; Mitchell, Gregory C; Hellstrom, Wayne J G

    2014-06-01

    The treatment of Peyronie's disease (PD) is a challenge for the clinician. In the quest to straighten the penis, alleviate pain, prevent further shortening, and restore erectile function, many non-surgical treatments have been offered in lieu of an operative approach, which is still considered the gold standard for definitive treatment. This communication is an update on the different approaches used in the minimally invasive management of this frustrating and yet intriguing condition.

  1. Minimally invasive veneers: current state of the art.

    PubMed

    Vanlıoğlu, Burçin Akoğlu; Kulak-Özkan, Yasemin

    2014-01-01

    Ceramic veneers are considered a conservative solution for patients requiring improvement of the shape, color, or position of their anterior teeth. Ceramic veneers have been extensively and successfully used to mask intrinsic staining, to give the appearance of straightening, and to correct minor malformations of anterior teeth without the removal of substantial amounts of sound tooth substance. The current literature was reviewed to search for the most important parameters determining the long-term success and correct application of ceramic veneers.

  2. [Problems of otorhinolaryngologists in perinatology (author's transl)].

    PubMed

    Collo, D

    1977-06-30

    Some of demonstrable pathological changes which are already present during the perinatal period are described in this work. Since nasal septal deviations due to trauma at birth can be straightened out immediately and often no special set of instruments are required, the importance of routine E-N-T-examinations is stressed. Such otorhinolaryngologic examinations were performed by the author in 1030 nearly born babys. Out of this number 19 birth traumatic nasal septal deviations were corrected without surgery.

  3. Overcoming Robot-Arm Joint Singularities

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Houck, J. A.

    1986-01-01

    Kinematic equations allow arm to pass smoothly through singular region. Report discusses mathematical singularities in equations of robotarm control. Operator commands robot arm to move in direction relative to its own axis system by specifying velocity in that direction. Velocity command then resolved into individual-joint rotational velocities in robot arm to effect motion. However, usual resolved-rate equations become singular when robot arm is straightened.

  4. Impact of crooked nose rhinoplasty on observer perceptions of attractiveness.

    PubMed

    Roxbury, Christopher; Ishii, Masaru; Godoy, Andres; Papel, Ira; Byrne, Patrick J; Boahene, Kofi D O; Ishii, Lisa E

    2012-04-01

    To evaluate the impact of a crooked nose on observer perceptions of facial asymmetry and attractiveness and the ability of rhinoplasty to minimize it. We hypothesized that the presence of a crooked nose would penalize symmetry and attractiveness ratings as compared to normal faces. We further hypothesized that straightening rhinoplasty would restore symmetry and improve attractiveness. Randomized controlled experiment. A group of 39 naïve observers viewed pictures of patients with crooked noses before and after straightening rhinoplasty, and normal patients. Observers rated the overall asymmetry and attractiveness, and the asymmetry of facial subunits using a survey with a rating scale of 1 to 10 for each category. For asymmetry, patient group (preoperative, postoperative, normal) was statistically significant by multivariate analysis of the variance. Post-analysis of variance showed significant differences in asymmetry scores for overall, nose subunit, and mouth subunit. Pairwise testing then showed significantly different overall asymmetry scores between normal and preoperative (P < .001), and preoperative and postoperative (P < .001), but not between normal and postoperative (P = .215) groups. Mixed linear regression analysis showed that decreasing nasal asymmetry by 1 point increases attractiveness by 0.18 points or 0.082 attractiveness standard deviations (P < .001). Faces with crooked noses were rated less symmetrical overall and less symmetrical at the nose and mouth subunits as compared to normal and postoperative faces. Straightening rhinoplasty diminished overall facial asymmetry and subunit asymmetry scores. Decreasing nasal asymmetry led to significant improvements in facial attractiveness. These data provide objective evidence supporting the idea that a straightening rhinoplasty can improve attractiveness. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  5. On quasi-periodic solutions of the 2+1 dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada equation

    NASA Astrophysics Data System (ADS)

    Cao, Cewen; Wu, Yongtang; Geng, Xianguo

    1999-05-01

    The 2+1 dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada equation is decomposed into systems of integrable ordinary differential equations resorting to the nonlinearization of Lax pairs. The Abel-Jacobi coordinates are introduced to straighten the flows, from which quasi-periodic solutions of the 2+1 dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada equation are obtained in terms of Riemann theta functions.

  6. Analysis of data on absorption in the northern part of the milky way

    NASA Technical Reports Server (NTRS)

    Polishchuk, E. P.

    1973-01-01

    The values of absorption for different galactic longitudes are obtained on the basis of star cluster data. It is found that the distance up to the point, where the straightening of the absorption distribution curve begins, depends on the limiting magnitude of the catalogue and the density of absorbing matter near the sun. The picture of absorbing matter distribution in the northern part of the Milky Way is given.

  7. JPRS Report China.

    DTIC Science & Technology

    1988-03-08

    efforts to improve the investment environment. The Zhejiang Airline Company went into operation, and program- controlled telephones in Hangzhou...communications and transportation must strictly enforce the State Council’s regulations governing the control of prices for the important means of produc... improvement of people’s living standard if the price problem is not gradually straightened out. Therefore, we should combine control with guidance in

  8. The Relationship between the Structural Geometry of Textile Fabrics and their Physical Properties. 1. Literature Review

    DTIC Science & Technology

    1948-08-01

    Peirce (26,27) comments on crimp distribution as a factor of prime importance in determining fabric strength and elongation. The straightening of...fabric. Simon (3k) underscores the importance of the direction of abrasion and recommends orientation of the lining fabrics of men’s apparel In...with ex- tension of the geometrical concepts proposed by Peirce (26) while the reaminder will provide empirical confirmation of the princi- ples

  9. Tarantula myosin free head regulatory light chain phosphorylation stiffens N-terminal extension, releasing it and blocking its docking back.

    PubMed

    Alamo, Lorenzo; Li, Xiaochuan Edward; Espinoza-Fonseca, L Michel; Pinto, Antonio; Thomas, David D; Lehman, William; Padrón, Raúl

    2015-08-01

    Molecular dynamics simulations of smooth and striated muscle myosin regulatory light chain (RLC) N-terminal extension (NTE) showed that diphosphorylation induces a disorder-to-order transition. Our goal here was to further explore the effects of mono- and diphosphorylation on the straightening and rigidification of the tarantula myosin RLC NTE. For that we used MD simulations followed by persistence length analysis to explore the consequences of secondary and tertiary structure changes occurring on RLC NTE following phosphorylation. Static and dynamic persistence length analysis of tarantula RLC NTE peptides suggest that diphosphorylation produces an important 24-fold straightening and a 16-fold rigidification of the RLC NTE, while monophosphorylation has a less profound effect. This new information on myosin structural mechanics, not fully revealed by previous EM and MD studies, add support to a cooperative phosphorylation-dependent activation mechanism as proposed for the tarantula thick filament. Our results suggest that the RLC NTE straightening and rigidification after Ser45 phosphorylation leads to a release of the constitutively Ser35 monophosphorylated free head swaying away from the thick filament shaft. This is so because the stiffened diphosphorylated RLC NTE would hinder the docking back of the free head after swaying away, becoming released and mobile and unable to recover its original interacting position on activation.

  10. Tarantula Myosin Free Head Regulatory Light Chain Phosphorylation Stiffens N-terminal Extension Releasing it and Blocking its Docking Back

    PubMed Central

    Alamo, Lorenzo; Li, Xiaochuan (Edward); Espinoza-Fonseca, L. Michel; Pinto, Antonio; Thomas, David D.; Lehman, William; Padrón, Raúl

    2015-01-01

    Molecular dynamics simulations of smooth and striated muscle myosin regulatory light chain (RLC) N-terminal extension (NTE) showed that diphosphorylation induces a disorder-to-order transition. Our goal here was to further explore the effects of mono- and diphosphorylation on the straightening and rigidification of the tarantula myosin RLC NTE. For that we used MD simulations followed by persistence length analysis to explore the consequences of secondary and tertiary structure changes occurring on RLC NTE following phosphorylation. Static and dynamic persistence lengths analysis of tarantula RLC NTE peptides suggest that diphosphorylation produces an important 24-fold straightening and a 16-fold rigidification of the RLC NTE, while monophosphorylation has a less profound effect. This new information on myosin structural mechanics, not fully revealed by previous EM and MD studies, add support to a cooperative phosphorylation-dependent activation mechanism as proposed for the tarantula thick filament. Our results suggest that the RLC NTE straightening and rigidification after Ser45 phosphorylation leads to a release of the constitutively Ser35 monophosphorylated free head swaying away from the thick filament shaft in the relaxed state. This is so because the stiffened diphosphorylated RLC NTE would hinder the docking back of the free head after swaying away, becoming released and mobile and unable to recover its original interacting position on activation. PMID:26038302

  11. Penile plication for Peyronie's disease: our results with mean follow-up of 103 months on 89 patients.

    PubMed

    Cantoro, U; Polito, M; Catanzariti, F; Montesi, L; Lacetera, V; Muzzonigro, G

    2014-01-01

    To evaluate the outcome of the long-term follow-up in patients who underwent corporoplasty-straightening treatment for Peyronie's disease. Between 1990 and 2012, a total of 89 patients underwent corporoplasty-straightening surgery using penile plication for Peyronie's disease. We followed up on all the patients for the following: (a) the correction of the curvature; (b) any penile shortening; (c) sexual function; and (d) complications. The mean follow-up period was 103 months. Complete correction of the curvature was obtained in 81 patients (91%). Shortening of the penis (1.5 to <3 cm) occurred in 20 patients (22.5%) and 79 patients (88.7%) had good erectile function (International Index of Erectile Function (IIEF) 5> 21). The most frequent complication was the sensitivity reduction of the glans in eight patients (8.9%), which was resolved within about a year after surgery (mean 11 months) and the shortening of the penis in 20 patients (22.5%), which, however, did not result in problems during sexual intercourse. Corporoplasty using penile straightening plication is a safe procedure whose results are maintained for even many years after surgery. It is a procedure that can be applied to any type of curvature. Any reduction in the length of the penis, as a result of the surgery procedure, does not lead to difficulties in sexual intercourse.

  12. Analysis of Internal Cracks in Continuous Casting Slabs with Soft Reduction

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Zhang, Jiongming; Xiao, Chao; Wang, Shunxi; Song, Wei

    2016-03-01

    The formation of internal cracks in continuous casting slabs is mainly attributed to the strain status and microsegregation near the solidifying front of the slabs. By analyzing the internal cracks of medium carbon microalloy steel, the obtained conclusions are that C, P, S, etc. enrich in dendrites and exist in grain boundaries, but these are just the internal causes, and the root cracking causes the tensile stress of solidification front. When the slab passes through the straightening segments, the liquid core thickness is large, and the liquid steel in the space of columnar crystals is not completely frozen. Therefore, the reduction effect of rollers results in the strain of solidification front exceeding the critical value. However, the corresponding strain in the arc and horizontal segments does not exceed this critical value, so the solidification front in the straightening segments would be much easy to crack. The statistics analysis shows that after soft reduction and straightening process are separately carried out, the occurrence rate of intermediate cracks is reduced by 41.3%.

  13. Void and pore formation inside the hair cortex by a denaturation and super-contraction process occurring during hair setting with hot irons.

    PubMed

    Gamez-Garcia, Manuel

    2011-01-01

    An analysis of hair fibers from donors that frequently use hot irons for hair straightening showed the presence of multiple pores and voids (φ approximately 0.1-1.5 μm) that extend from the cuticle sheath to regions inside the hair cortex. Pore formation in the cortex was found to be confined at its periphery and could be reproduced in the laboratory with virgin hair fibers after the application of various hot-iron straightening cycles. The appearance of pores and voids in the cortex was found to be associated to the production of hot water vapor while the fiber is undergoing mechanical elongation or contraction. The number of pores was seen to rapidly increase with temperature in the range from 190 to 220°C and also with the number of straightening cycles. Larger hair voids (φ approximately 2-5 μm) were also detected in the cortex. The small pores found at the cortex periphery appear to occur by the simultaneous occurrence of rearrangement of hair proteins, fiber mechanical contraction/expansion, and the flow of super-heated steam. Hot irons create, thus, the conditions for the onset of pore formation as the high temperatures produce superheated steam and soften the native state of hair proteins by a process involving denaturation and changes in the crystalline regions.

  14. Plication corporoplasty for congenital penile curvature: our results with long-term follow-up.

    PubMed

    Cantoro, Ubaldo; Polito, Massimo; Lacetera, Vito; Muzzonigro, Giovanni

    2014-09-01

    To evaluate the outcome of the long-term follow-up in patients who underwent corporoplasty-straightening treatment for congenital penile curvature (CPC). Between 1989 and 2012, a total of 60 patients underwent corporoplasty-straightening surgery using penile plication for CPC. We followed up on all the correction of the curvature; (a) any penile shortening; (b) sexual function; (c) complications. The mean follow-up period was of 98 months. Complete correction of the curvature was obtained in 54 patients (90 %). Shortening of the penis (1.5 to not more than 3 cm) occurred in 16 patients (26.6 %). All patients had good erectile function (IIEF-5 > 21). The most frequent complication was the sensitivity reduction of the glans in five patients (8.3 %), which was resolved with in about a year after surgery (mean 11 months) and the shortening of the penis in 16 patients (26.6 %), which, however, did not result in problems during sexual intercourse. Corporoplasty using penile straightening plication is a safe procedure whose results are maintained even after many years after surgery. It is a procedure that can be applied to any type of curvature. Any reduction in the length of the penis, as a result of the surgery procedure, does not lead to difficulties in sexual intercourse.

  15. Root Canal Shaping by Single-File Systems and Rotary Instruments: a Laboratory Study

    PubMed Central

    Bane, Khaly; Faye, Babacar; Sarr, Mouhamed; Niang, Seydina O; Ndiaye, Diouma; Machtou, Pierre

    2015-01-01

    Introduction: The aim of this study was to compare the shaping ability of two single-file systems and conventional rotary instruments in severely curved root canals of extracted human molars. Methods and Materials: Mesiobuccal canals of 120 mandibular molars with angles of curvature ranging between 25° and 35° and radii of curvature from 5 to 9 mm, were divided into three groups (n=40). In each group the canals were instrumented with either WaveOne (W), Reciproc (R) or ProTaper (P). The time required for canal shaping and the frequency of broken instruments were recorded. The standardized pre and post-instrumentation radiographs were taken to determine changes in working length (WL) and straightening of canal curvature. The presence of blockage or perforation was also evaluated. Data were analyzed using the one-way analysis of variance (ANOVA) and post-hoc Tukey’s test. The level of significance was set at 0.05. Results: Both single-instrument systems reduced the canal preparation time by approximately 50% (P<0.05). No incidence of broken instruments from single-file systems was reported; however, two F2 instruments in the P group were broken (P<0.05). Reduction in WL and straightening of canal curvature was observed in all three systems with the highest scores belonging to P system (P<0.05). No case of blockage or perforation was found during shaping in any group. Conclusion: Single-file systems shaped curved canals with substantial saving in time and a significant decrease in incidence of instrument separation, change in WL, and straightening of canal curvature. PMID:25834600

  16. SU-E-T-501: Initial Orthovoltage Beam Profile Analysis of a Small Brass MLC

    SciTech Connect

    Loughery, B; Snyder, M

    2015-06-15

    Purpose To create brass leaves for an orthovoltage MLC and take initial beam profile measurements. Methods The low-energy MLC was designed in previous work. Brass was chosen for its self-lubrication and low cost. Stock brass rectangles (30cm × 1.0cm × 0.5cm) were ordered with pre-cut gear rack along the topmost long edges. Leaf designs were translated into G-code, then cut with a Tormach CNC-1100 mill. Intense bowing was observed in the beam direction, which required straightening via an in-house jig. Straightened leaves were placed into MLC assembly and mounted to a 320 kVp orthovoltage tube. EDR2 film was irradiated in four situations: MLC open so one edge was isocentric, and MLC open more than isocentric, completely closed MLC, and an open field shot with the MLC removed. The first two scans tested penumbra for our rectangular edges due to unfocused design. The final two scans tested transmission and interleaf leakage. All four experiments were set to 120 kVp and 10 mA for two minutes. Results Transmission and interleaf leakage were found to be zero. Interleaf leakage is faintly visible on film, but undetected by our film scanner despite high spatial resolution. Penumbra at isocenter was found to be 0.72mm, which matched the penumbras of true field edges. Penumbra off-isocenter was 1.1mm. Mechanically, leaves are moving smoothly once straightened. Conclusion Beam profiles through our brass MLC are acceptable. Leaves attenuate and move as designed. Looking forward, we intend to animate our MLC to deliver more complicated treatment plans.

  17. Contemporary hazards in the home: keeping children safe from thermal injuries.

    PubMed

    Deave, Toity; Goodenough, Trudy; Stewart, Jane; Towner, Elizabeth; Majsak-Newman, Gosia; Hawkins, Adrian; Coupland, Carol; Kendrick, Denise

    2013-07-01

    To explore the knowledge and reported thermal injury prevention practices among parents of children aged 0-4 years in disadvantaged areas. Parents of pre-school children in Children's Centres in four study areas in England (Nottingham, Newcastle, Norwich and Bristol) were interviewed using a structured schedule. Interviews covered smoke alarms, bedtime routines, fire escape plans, other thermal prevention practices and parental knowledge of first aid. Of the 200 respondents, most reported ownership of at least one smoke alarm (n=191, 96%), of which 95% were working. Half reported a fire prevention bedtime routine (n=105, 53%) or fire escape plan (n=81, 42%). Most parents had matches or lighters in the home (n=159, 80%), some stored where children under 5 years of age could reach them (n=30, 19%). There was a high prevalence of irons (n=188, 94%) and hair straighteners (n=140, 70%). A third of both devices were used daily. Just 17 (12%) parents reported leaving hair straighteners, when hot but not in use, in a heatproof bag. Knowledge of correct initial first aid for a small burn was good (n=165, 83%), but parents reported other potentially harmful actions, for example, applying ointment (n=44, 22%). Most families report at least one working smoke alarm, but many do not have fire escape plans or fire prevention bedtime routines. A number of reported practices could compromise child safety, such as storage of matches or lighters and leaving hair straighteners to cool unprotected. Reappraisal of health promotion messages, in light of new household consumables, is necessary.

  18. Biaxial loading of arterial tissues with 3D in situ observations of adventitia fibrous microstructure: A method coupling multi-photon confocal microscopy and bulge inflation test.

    PubMed

    Cavinato, Cristina; Helfenstein-Didier, Clementine; Olivier, Thomas; du Roscoat, Sabine Rolland; Laroche, Norbert; Badel, Pierre

    2017-10-01

    Disorders in the wall microstructure underlie all forms of vascular disease, such as the aortic aneurysm, the rupture of which is necessarily triggered at the microscopic level. In this context, we developed an original experimental approach, coupling a bulge inflation test to multiphoton confocal microscopy, for visualizing the 3D micro-structure of porcine, human non-aneurysmal and aneurysmal aortic adventitial collagen under increasing pressurization. The experiment complexity on such tissues led to deeply address the acquisition major hurdles. The important innovative features of the methodology are presented, especially regarding region-of-interest tracking, definition of a stabilization period prior to imaging and correction of z-motion, z being the objective's axis. Such corrections ensured consistent 3D qualitative and quantitative analyses without z-motion. Qualitative analyses of the stable 3D images showed dense undulated collagen fiber bundles in the unloaded state which tended to progressive straightening and separation into a network of thinner bundles at high pressures. Quantitative analyses were made using a combination of weighted 2D structure tensors and fitting of 4 independent Gaussian functions to measure parameters related to straightening and orientation of the fibers. They denoted 3 principal fibers directions, approximately 45°, 135° and 90° with respect to the circumferential axis in the circumferential-axial plane without any evident reorientation of the fibers under pressurization. Results also showed that fibers at zero-pressure state were straighter and less dispersed in orientation for human samples - especially aneurysms - than for pigs. Progressive straightening and decrease in dispersion were quantified during the inflation. These findings provide further insight into the micro-architectural changes within the arterial wall. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Direct real-time detection of the actin-activated power stroke within the myosin catalytic domain.

    PubMed

    Muretta, Joseph M; Petersen, Karl J; Thomas, David D

    2013-04-30

    We have used transient kinetics, nanosecond time-resolved fluorescence resonance energy transfer (FRET), and kinetics simulations to resolve a structural transition in the Dictyostelium myosin II relay helix during the actin-activated power stroke. The relay helix plays a critical role in force generation in myosin, coupling biochemical changes in the ATPase site with the force-transducing rotation of the myosin light-chain domain. Previous research in the absence of actin showed that ATP binding to myosin induces a dynamic equilibrium between a bent prepower stroke state of the relay helix and a straight postpower stroke state, which dominates in the absence of ATP or when ADP is bound. We now ask whether actin binding reverses this transition and if so, how this reversal is coordinated with actin-activated phosphate release. We labeled a Cys-lite Dictyostelium myosin II motor domain with donor and acceptor probes at two engineered Cys residues designed to detect relay helix bending. We then performed transient time-resolved FRET following stopped-flow mixing of actin with labeled myosin, preincubated with ATP. We determined the kinetics of actin-activated phosphate release, using fluorescent phosphate-binding protein. The results show that actin binding to the myosin.ADP.P complex straightens the relay helix before phosphate dissociation. This actin-activated relay helix straightening is reversible, but phosphate irreversibly dissociates from the postpower stroke state, preventing reversal of the power stroke. Thus, relay helix straightening gates phosphate dissociation, whereas phosphate dissociation provides the thermodynamic driving force underlying force production.

  20. Use of a Non-cross-linked Xenograft (Xenform) in Surgical Treatment of Peyronie's Disease.

    PubMed

    Caraceni, Enrico; Leone, Luca; Utizi, Lilia; Marronaro, Angelo

    2016-09-01

    To evaluate the effectiveness in Peyronie's disease surgical treatment using Xenform, a non-cross-linked graft derived from dermal bovine tissue, to close the defect obtained after plaque incision, without penile prosthesis implant. A further objective is to evaluate the satisfaction of patients. We treated with plaque incision 28 patients with a stable penile curvature ≥60° hindering penetration and with erectile function conserved. International Index of Erectile Function-15 and a not-validated questionnaire constituted of 7 questions about their satisfaction were administered after 1 year of follow-up. Furthermore, specific questions were relative about penile straightening, penile postoperative length, glandular sensitivity, and feeling palpability. Graft is resulted compatible with albugineal features, like thickness, consistency, and elasticity; it is waterproof, allowing the visualization of complete correction of the curvature after the suture. No severe complications were observed except 1 hematoma requiring surgical revision. Sixteen patients were seen after at least 1 year of follow-up. Curvature improvement was obtained in all cases, with the complete straightening in 75%; we did not observe any retraction of the graft and any recurrence on the curvature. Significant reduced glans sensibility and erectile dysfunction were the more frequent postoperative complications, resulting in 43.8% and 25%, respectively. All patients are satisfied with the straightening. Only 2 patients are dissatisfied about the overall result. Plaque incision corporoplasty with Xenform graft is an effective and safe surgical treatment. Xenform is a secure and a reliable albugineal substitute, comparable to other heterologous graft. We have not observed any retraction. Patient's satisfaction is linked to the treatment result and to sexual life. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. A clean air continuous flow propulsion facility

    NASA Technical Reports Server (NTRS)

    Krauss, R. H.; Mcdaniel, J. C., Jr.

    1992-01-01

    Consideration is given to a contaminant-free, high enthalpy, continuous flow facility designed to obtain detailed code validation measurements of high speed combustion. The facility encompasses uncontaminated air temperature control to within 5 K, fuel temperature control to 2 K, a ceramic flow straightener, drying of inlet air, and steady state continuous operation. The air heating method provides potential for independent control of contaminant level by injection, mixing, and heating upstream. Particular attention is given to extension of current capability of 1250 K total air temperature, which simulates Scramjet enthalpy at Mach 5.

  2. Turbulent dispersion via fan-generated flows

    PubMed Central

    Halloran, Siobhan K.; Wexler, Anthony S.; Ristenpart, William D.

    2014-01-01

    Turbulent dispersion of passive scalar quantities has been extensively studied in wind tunnel settings, where the flow is carefully conditioned using flow straighteners and grids. Much less is known about turbulent dispersion in the “unconditioned” flows generated by fans that are ubiquitous in indoor environments, despite the importance of these flows to pathogen and contaminant transport. Here, we demonstrate that a point source of scalars released into an airflow generated by an axial fan yields a plume whose width is invariant with respect to the fan speed. The results point toward a useful simplification in modeling of disease and pollution spread via fan-generated flows. PMID:24932096

  3. Gravitational Smoothing of Kinks on Cosmic String Loops.

    PubMed

    Wachter, Jeremy M; Olum, Ken D

    2017-02-03

    We analyze the effect of gravitational backreaction on cosmic string loops with kinks, which is an important determinant of the shape, and thus the potential observability, of string loops which may exist in the Universe today. Kinks are not rounded off, but may be straightened out. This means that backreaction will only cause loops with kinks to develop cusps after some potentially large fraction of their lifetimes. In some loops, symmetries prevent even this process, so that the loop evaporates in a self-similar fashion and the kinks are unchanged. As an example, we discuss backreaction on the rectangular Garfinkle-Vachaspati loop.

  4. Gravitational Smoothing of Kinks on Cosmic String Loops

    NASA Astrophysics Data System (ADS)

    Wachter, Jeremy M.; Olum, Ken D.

    2017-02-01

    We analyze the effect of gravitational backreaction on cosmic string loops with kinks, which is an important determinant of the shape, and thus the potential observability, of string loops which may exist in the Universe today. Kinks are not rounded off, but may be straightened out. This means that backreaction will only cause loops with kinks to develop cusps after some potentially large fraction of their lifetimes. In some loops, symmetries prevent even this process, so that the loop evaporates in a self-similar fashion and the kinks are unchanged. As an example, we discuss backreaction on the rectangular Garfinkle-Vachaspati loop.

  5. Plasmastatic model of toroidal trap “Galatea-belt”

    NASA Astrophysics Data System (ADS)

    Brushlinskii, K. V.; Goldich, A. S.

    2017-01-01

    Magnetic galatea-traps for thermonuclear plasma confinement with current carrying conductors immersed into the plasma volume, are represented by an example of the toroidal trap “The Belt” with two circular conductors. Numerical models of equilibrium plasma and field configurations are investigated in straightened into cylinder analogues of some toroidal galateas in a series of works by the authors. This paper presents a plasmastatic model of configurations in the toroidal variant of “The Belt” in terms of a boundary problem with the Grad-Shafranov equation. Distinctions of their geometry and quantitative characteristics from the cylindrical analogues and their dependence of parameters are determined in computation.

  6. An intercomparison of NEL and DHL water flow facilities using a twin orifice plate flowmeter assembly

    NASA Technical Reports Server (NTRS)

    Dejong, J.; Spencer, E. A.

    1983-01-01

    A 205 mm transfer standard orifice plate meter assembly, consisting of two orifice plates in series separated by a length of pipe containing a flow straightener, was calibrated in two water flow facilities. Results show that the agreement in the characteristics of such a differential pressure transfer standard package is within 0.17% over a 10:1 range from flow rates of approximately 8 to 80 l/sec. When the range over which the comparison was made was limited to that for which the calibration graphs gave straight lines, the agreement is 0.1% in 3 of the 4 calibrations (0.17% in the fourth).

  7. An imaging and analysis toolset for the study of Caenorhabditis elegans neurodevelopment

    NASA Astrophysics Data System (ADS)

    Christensen, Ryan; Bokinsky, Alexandra; Santella, Anthony; Wu, Yicong; Marquina, Javier; Kovacevic, Ismar; Kumar, Abhishek; Winter, Peter; McCreedy, Evan; Mohler, William; Bao, Zhirong; Colón-Ramos, Daniel; Shroff, Hari

    2015-03-01

    How an entire nervous system develops remains mysterious. We have developed a light-sheet microscope system to examine neurodevelopment in C. elegans embryos. Our system creates overlapping light sheets from two orthogonally positioned objectives, enabling imaging from the first cell division to hatching (~14 hours) with 350 nm isotropic resolution. We have also developed computer algorithms to computationally straighten nematode embryos, facilitating data comparison and combination from multiple animals. We plan to use these tools to create an atlas showing the position and morphology of all neurons in the developing embryo.

  8. Surgical orthodontic correction of mandibular laterognathism

    PubMed Central

    Singh, Harpreet; Srivastava, Dhirendra; Kapoor, Pranav; Sharma, Poonam

    2016-01-01

    This case report describes the successful treatment of a patient with mandibular laterognathism and associated facial asymmetry with combined surgical orthodontic approach. After 7 months of presurgical orthodontic treatment, intraoral vertical ramus osteotomy, and straightening genioplasty were performed as two step surgeries to reposition the deviated mandible and chin, respectively. The total active treatment period was 14 months. After surgical orthodontic treatment, significant improvement in occlusion, masticatory function, and facial appearance was discernible. Posttreatment records at 3 years showed stable results with good occlusion. PMID:27127755

  9. New surgical treatment for Peyronie disease.

    PubMed

    Essed, E; Schroeder, F H

    1985-06-01

    Five patients with Peyronie disease were treated successfully with a surgical technique derived from Nesbit's technique for the treatment of congenital curvature of the penis. Excision of ellipses of tunica albuginea from the convex side of the penis as described by Nesbit was not done, but instead the tunica was reeved with nonresorbable sutures to achieve straightening. The surgical technique combined with prior radiotherapy was successfully applied to patients with severe forms of Peyronie disease. More experience is necessary to establish the value of the proposed treatment concept.

  10. High Average Power Laser Gain Medium With Low Optical Distortion Using A Transverse Flowing Liquid Host

    DOEpatents

    Comaskey, Brian J.; Ault, Earl R.; Kuklo, Thomas C.

    2005-07-05

    A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.

  11. The application of trigonal curve to the Mikhailov-Shabat-Sokolov flows

    NASA Astrophysics Data System (ADS)

    He, Guoliang; Geng, Xianguo; Wu, Lihua

    2016-08-01

    Resorting to the characteristic polynomial of Lax matrix for the Mikhailov-Shabat-Sokolov hierarchy associated with a {3 × 3} matrix spectral problem, we introduce a trigonal curve, from which we deduce the associated Baker-Akhiezer function, meromorphic functions and Dubrovin-type equations. The straightening out of the Mikhailov-Shabat-Sokolov flows is exactly given through the Abel map. On the basis of these results and the theory of trigonal curve, we obtain the explicit theta function representations of the Baker-Akhiezer function, the meromorphic functions, and in particular, that of solutions for the entire Mikhailov-Shabat-Sokolov hierarchy.

  12. Stratigraphic evidence for millennial-scale temporal clustering of earthquakes on a continental-interior fault: Holocene Mississippi River floodplain deposits, New Madrid seismic zone, USA

    NASA Astrophysics Data System (ADS)

    Holbrook, John; Autin, Whitney J.; Rittenour, Tammy M.; Marshak, Stephen; Goble, Ronald J.

    2006-07-01

    The earthquake cycles that characterize continental-interior areas that are far from active plate boundaries have proven highly cryptic and difficult to resolve. We used a novel paleoseismic proxy to address this issue. Namely, we reconstructed Holocene Mississippi River channels from maps of floodplain strata in order to identify channel perturbations reflective of major displacement events on the high-hazard and mid-plate Reelfoot thrust fault, New Madrid seismic zone, U.S.A. Only three discrete slip events are currently documented for the Reelfoot fault (˜ AD 900, ˜ AD 1450, and AD 1812). This study extends this record and, thus, illustrates the utility of stratigraphic proxies as paleoseismic tools. We concurrently offer here some of the first quantified response times for tectonically induced channel pattern changes in large alluvial rivers. We identified at least two cycles of pervasive meandering that were interrupted by channel-straightening responses occurring upstream of the Reelfoot fault scarp. These straightening responses initiated at 2244 BC +/- 269 to 1620 BC +/- 220 and ˜ AD 900, respectively, and each records initiation of a period of Reelfoot fault slip after millennia of relative tectonic quiescence. The second (or New Madrid) straightening response was triggered by the previously known ˜ AD 900 fault slip event, and this initial low sinuosity has been protracted until the modern day by the latter ˜ AD 1450 and AD 1812 events. The first (or Bondurant) straightening response began a period of several hundred to ˜ 1400 years of low river sinuosity which evidences a similar period of multiple recurrent displacement events on the Reelfoot fault. These Bondurant events predate the existing paleoseismic record for the Reelfoot fault. These data offer initial evidence that slip events on the Reelfoot fault were temporally clustered on millennial scales and, thus, offers the first direct evidence for millennial-scale clustering of earthquakes on a

  13. Transsexuals' sexual stories.

    PubMed

    Schrock, Douglas P; Reid, Lori L

    2006-02-01

    When viewed through a popular cultural lens, male-to-female transsexuals' sexual biographies can appear to indicate male transvestitism, heterosexuality, or homosexuality rather than transsexuality. How do transsexuals subvert such implications and construct transsexual identities? Drawing on K. Plummer's (1995) approach to sexual stories, we examine how nine male-to-female transsexuals construct their sexual pasts to accomplish what sociologists call "identity work." Interviewees used gendered sexual scripts, cultural discourse on the biological basis of male sexual arousal, and a discourse of therapeutic individualism to narratively defetishize autoerotic crossdressing, queer straight sex, refashion transvestic sex, and straighten out gay sex.

  14. Atomistic Model of Physical Ageing in Se-rich As-Se Glasses

    SciTech Connect

    Golovchak,R.; Shpotyuk, O.; Kozdras, A.; Bureau, B.; Vlcek, M.; Ganjoo, A.; Jain, H.

    2007-01-01

    Thermal, optical, X-ray excited and magnetic methods were used to develop a microstructural model of physical ageing in Se-rich glasses. The glass composition As10Se90, possessing a typical cross-linked chain structure, was chosen as a model object for the investigations. The effect of physical ageing in this glass was revealed by differential scanning calorimetry, whereas the corresponding changes in its atomic arrangement were studied by extended X-ray absorption fine structure, Raman and solid-state 77Se nuclear magnetic resonance spectroscopy. Straightening-shrinkage processes are shown to be responsible for the physical ageing in this Se-rich As-Se glass.

  15. Radial nerve palsy caused by spontaneously occurring nerve torsion. Case report.

    PubMed

    Fernandez, E; Di Rienzo, A; Marchese, E; Massimi, L; Lauretti, L; Pallini, R

    2001-04-01

    An 18-year-old man presented with a spontaneously occurring radial nerve palsy that spared the triceps muscle. At surgery, the portion of the radial nerve located at the midarm level had an hourglass-like appearance. Under magnification, an external-internal neurolysis of the narrowed portion of the hourglass-shaped portion revealed nerve torsion. Straightening of the twisted nerve and fixation accomplished using epiperineurium-fascia stitches to avoid a new torsion resulted in complete functional recovery of the radial nerve.

  16. Contingency Pest and Vector Surveillance

    DTIC Science & Technology

    2013-11-01

    Jeweler’s 5 Flashlight 2 Gloves, disposable rubber / silicone 10 pairs or 1box Hammer, claw 1 Jars, storage, plastic (Nalgene, 1 pint) 6 Knife...colored cotton muslin cloth, germination paper, or paper towel attached with rubber bands, is placed inside the jar and held in place with a large...square of flannel or other “fuzzy” material attached to the end of a piece of heavy-gauge wire (such as a straightened-out clothes hanger) with rubber

  17. A clean air continuous flow propulsion facility

    NASA Technical Reports Server (NTRS)

    Krauss, R. H.; Mcdaniel, J. C., Jr.

    1992-01-01

    Consideration is given to a contaminant-free, high enthalpy, continuous flow facility designed to obtain detailed code validation measurements of high speed combustion. The facility encompasses uncontaminated air temperature control to within 5 K, fuel temperature control to 2 K, a ceramic flow straightener, drying of inlet air, and steady state continuous operation. The air heating method provides potential for independent control of contaminant level by injection, mixing, and heating upstream. Particular attention is given to extension of current capability of 1250 K total air temperature, which simulates Scramjet enthalpy at Mach 5.

  18. Flow quality studies of the NASA Lewis Research Center 8- by 6-foot supersonic/9- by 15-foot low speed wind tunnel

    NASA Technical Reports Server (NTRS)

    Arrington, E. Allen; Pickett, Mark T.

    1992-01-01

    A series of studies were conducted to determine the existing flow quality in the NASA Lewis 8 by 6 Foot Supersonic/9 by 15 Foot Low speed Wind Tunnel. The information gathered from these studies was used to determine the types and designs of flow manipulators which can be installed to improve overall tunnel flow quality and efficiency. Such manipulators include honeycomb flow straighteners, turbulence reduction screens, corner turning vanes, and acoustic treatments. The types of measurements, instrumentation, and results obtained from experiments conducted at several locations throughout the tunnel loop are described.

  19. Finite-difference solution for turbulent swirling compressible flow in axisymmetric ducts with struts

    NASA Technical Reports Server (NTRS)

    Anderson, O. L.

    1974-01-01

    A finite-difference procedure for computing the turbulent, swirling, compressible flow in axisymmetric ducts is described. Arbitrary distributions of heat and mass transfer at the boundaries can be treated, and the effects of struts, inlet guide vanes, and flow straightening vanes can be calculated. The calculation procedure is programmed in FORTRAN 4 and has operated successfully on the UNIVAC 1108, IBM 360, and CDC 6600 computers. The analysis which forms the basis of the procedure, a detailed description of the computer program, and the input/output formats are presented. The results of sample calculations performed with the computer program are compared with experimental data.

  20. Brazilian keratin hair treatment: a review.

    PubMed

    Weathersby, Courtney; McMichael, Amy

    2013-06-01

    Brazilian keratin treatments are widely available products that are used by women all over the world to straighten hair. Marketers of these products claim that the keratin treatments render naturally curly hair more manageable and frizz-free while enhancing color and shine, giving the hair a healthier appearance. Although widely used, there have been virtually no reports of adverse side effects. Unfortunately, many of the products that are applied by salon professionals contain formaldehyde or its derivatives and are being marketed as safe.

  1. Hydrodynamic solutions at a sonic-boom focus

    NASA Technical Reports Server (NTRS)

    Parker, L. W.; Zalosh, R. G.

    1974-01-01

    Study of the focusing of sonic-boom N waves using a numerical shock-following method. The computer code used in the calculations employs a moving mesh so that weak N wave shocks can be followed for large distances without numerical dissipation. In several sample calculations, overpressures at the focus ranging from 2 to 20 times the nominal overpressure have been computed. It is also found that weak shocks tend to cusp at the axis in accord with the geometric-acoustics description, whereas strong shocks straighten out without cusping.

  2. [Polish Gynecologic Society guidelines on perinatal care and delivery management].

    PubMed

    Krzysztof, Czajkowski

    2009-07-01

    Recommendations concerning antenatal care and the management of labour were worked out in order to straighten basic standards of care in pregnancies near term. Problems with recognition of labour, indications for hospitalization and necessary procedures as well as principles of fetal monitoring during labour were discussed. In addition basic principles of induction and preinduction of labour, amniotomy and stimulation of uterine contractions and the management of different stages of labour were presented. The diagnostic criteria of prolonged, obstructed labour and intrauterine infection were shown. The necessity of adequate documentation of labour was emphasized.

  3. Hair Cosmetics: An Overview

    PubMed Central

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  4. Capelli bitableaux and Z-forms of general linear Lie superalgebras.

    PubMed Central

    Brini, A; Teolis, A G

    1990-01-01

    The combinatorics of the enveloping algebra UQ(pl(L)) of the general linear Lie superalgebra of a finite dimensional Z2-graded Q-vector space is studied. Three non-equivalent Z-forms of UQ(pl(L)) are introduced: one of these Z-forms is a version of the Kostant Z-form and the others are Lie algebra analogs of Rota and Stein's straightening formulae for the supersymmetric algebra Super[L P] and for its dual Super[L* P*]. The method is based on an extension of Capelli's technique of variabili ausiliarie to algebras containing positively and negatively signed elements. PMID:11607048

  5. Turbulent dispersion via fan-generated flows

    NASA Astrophysics Data System (ADS)

    Halloran, Siobhan K.; Wexler, Anthony S.; Ristenpart, William D.

    2014-05-01

    Turbulent dispersion of passive scalar quantities has been extensively studied in wind tunnel settings, where the flow is carefully conditioned using flow straighteners and grids. Much less is known about turbulent dispersion in the "unconditioned" flows generated by fans that are ubiquitous in indoor environments, despite the importance of these flows to pathogen and contaminant transport. Here, we demonstrate that a point source of scalars released into an airflow generated by an axial fan yields a plume whose width is invariant with respect to the fan speed. The results point toward a useful simplification in modeling of disease and pollution spread via fan-generated flows.

  6. Dynamic fluctuations of dipolar semiflexible filaments

    NASA Astrophysics Data System (ADS)

    Belovs, M.; Cěbers, A.

    2006-02-01

    On the basis of the model of a flexible magnetic filament, the characteristics of their thermal fluctuations are considered. The crossover of the time dependence of the mean quadratic displacement from t3/4 to t1/2 at the magnetic field increase is found. Two characteristic mechanisms of the magnetization relaxation time distribution—straightening of the thermal undulations and excitation of the bending modes of the free ends under the action of an ac magnetic field—are described. In both cases, the characteristic scaling law ω-3/4 of the magnetic susceptibility in a high-frequency range is found.

  7. Dynamics of flexible fibers in shear flow

    SciTech Connect

    Słowicka, Agnieszka M.; Wajnryb, Eligiusz; Ekiel-Jeżewska, Maria L.

    2015-09-28

    Dynamics of flexible non-Brownian fibers in shear flow at low-Reynolds-number are analyzed numerically for a wide range of the ratios A of the fiber bending force to the viscous drag force. Initially, the fibers are aligned with the flow, and later they move in the plane perpendicular to the flow vorticity. A surprisingly rich spectrum of different modes is observed when the value of A is systematically changed, with sharp transitions between coiled and straightening out modes, period-doubling bifurcations from periodic to migrating solutions, irregular dynamics, and chaos.

  8. Nanotube Alignment And Dispersion In Epoxy Resin

    NASA Astrophysics Data System (ADS)

    Ewels, C. P.; Désarmot, G.; Foutel-Richard, A.; Martin, F.

    2003-10-01

    To date theoretically predicted enhancements of Youngs' Modulus, failure strength, and other mechanical properties of nanotube-composite materials have not been experimentally realised. We discuss the reasons for this and using short fibre composite theory suggest that nanotube straightness is a crucial factor. We examine single walled nanotube — epoxy resin (LY556) composites using microindentation, 3-point bending, electrical resistivity and various microscopy techniques. We test extrusion as a method for aligning the nanotubes, and the use of gum arabic for tube dispersion, straightening and separation.

  9. Root canal shaping using rotary nickel-titanium files in preclinical dental education in Turkey.

    PubMed

    Ünal, Gül Çelik; Maden, Murat; Orhan, Ekim Onur; Sarıtekin, Erdal; Teke, Anıl

    2012-04-01

    The purposes of this study were to evaluate the ability of a group of third-year dental students without any endodontic clinical experience to use the ProTaper Instruments (Dentsply Maillefer) to decrease the amount of straightening of curved canals on human molar teeth and to determine the incidence of instrument fractures and instrumentation time. Thirty-one undergraduate dental students in Turkey received a training session. The students prepared a total of 144 root canals in human mandibular or maxillary molar teeth with ProTaper. Fifty-six teeth were excluded due to unreadable image, misinformation, or straight or severe curve. Using pre- and post-preparation digital radiographs, the straightening of curved root canals was investigated. Loss of working length and incidence of fracture were also noted. A total of eighty-eight curved root canals were selected. Mesiobuccal or mesiolingual roots with curvatures of between 20° and 43° as assessed by Schneider's method and working length of between 15 mm and 22.5 mm were included in the study. The means of the curved root canals before and after the instrumentation were 29.5° ± 6° and 27° ± 6.3°, respectively. The means of the working length before and after the instrumentation were 19 mm ± 2.1 mm and 18.3 mm ± 1.9 mm, respectively. A statistically significant difference between straightening of curved root canals and loss of working length was found between before and after instrumentation (p<0.000). The mean straightening of curved root canals and loss of working length after preparation with the size F1 ProTaper file were 2.5 mm ± 3.6 mm and 0.7 mm ± 0.6 mm, respectively. Only two F1 ProTaper instruments fractured at the apical level. The study concluded that rotary instruments performed adequately with inexperienced operators who received a brief structured training session.

  10. Finite-band solutions of the coupled dispersionless hierarchy

    NASA Astrophysics Data System (ADS)

    Li, Zhu

    2016-08-01

    The coupled dispersionless hierarchy is derived with the help of the zero curvature equation. Based on the Lax matrix, we introduce an algebraic curve {{ K }}n of arithmetic genus n, from which we establish the corresponding meromorphic function ϕ, the Baker-Akhiezer function {\\varphi }1, and Dubrovin-type equations. The straightening out of all the flows is given under the Abel-Jacobi coordinates. Using the asymptotic properties of ϕ and {\\varphi }1, we obtain the explicit theta function representations of the meromorphic function ϕ, the Baker-Akhiezer function {\\varphi }1 and of solutions for the whole hierarchy.

  11. Ultra High-Resolution In vivo Computed Tomography Imaging of Mouse Cerebrovasculature Using a Long Circulating Blood Pool Contrast Agent.

    PubMed

    Starosolski, Zbigniew; Villamizar, Carlos A; Rendon, David; Paldino, Michael J; Milewicz, Dianna M; Ghaghada, Ketan B; Annapragada, Ananth V

    2015-05-18

    Abnormalities in the cerebrovascular system play a central role in many neurologic diseases. The on-going expansion of rodent models of human cerebrovascular diseases and the need to use these models to understand disease progression and treatment has amplified the need for reproducible non-invasive imaging methods for high-resolution visualization of the complete cerebral vasculature. In this study, we present methods for in vivo high-resolution (19 μm isotropic) computed tomography imaging of complete mouse brain vasculature. This technique enabled 3D visualization of large cerebrovascular networks, including the Circle of Willis. Blood vessels as small as 40 μm were clearly delineated. ACTA2 mutations in humans cause cerebrovascular defects, including abnormally straightened arteries and a moyamoya-like arteriopathy characterized by bilateral narrowing of the internal carotid artery and stenosis of many large arteries. In vivo imaging studies performed in a mouse model of Acta2 mutations demonstrated the utility of this method for studying vascular morphometric changes that are practically impossible to identify using current histological methods. Specifically, the technique demonstrated changes in the width of the Circle of Willis, straightening of cerebral arteries and arterial stenoses. We believe the use of imaging methods described here will contribute substantially to the study of rodent cerebrovasculature.

  12. Ultra High-Resolution In vivo Computed Tomography Imaging of Mouse Cerebrovasculature Using a Long Circulating Blood Pool Contrast Agent

    PubMed Central

    Starosolski, Zbigniew; Villamizar, Carlos A.; Rendon, David; Paldino, Michael J.; Milewicz, Dianna M.; Ghaghada, Ketan B.; Annapragada, Ananth V.

    2015-01-01

    Abnormalities in the cerebrovascular system play a central role in many neurologic diseases. The on-going expansion of rodent models of human cerebrovascular diseases and the need to use these models to understand disease progression and treatment has amplified the need for reproducible non-invasive imaging methods for high-resolution visualization of the complete cerebral vasculature. In this study, we present methods for in vivo high-resolution (19 μm isotropic) computed tomography imaging of complete mouse brain vasculature. This technique enabled 3D visualization of large cerebrovascular networks, including the Circle of Willis. Blood vessels as small as 40 μm were clearly delineated. ACTA2 mutations in humans cause cerebrovascular defects, including abnormally straightened arteries and a moyamoya-like arteriopathy characterized by bilateral narrowing of the internal carotid artery and stenosis of many large arteries. In vivo imaging studies performed in a mouse model of Acta2 mutations demonstrated the utility of this method for studying vascular morphometric changes that are practically impossible to identify using current histological methods. Specifically, the technique demonstrated changes in the width of the Circle of Willis, straightening of cerebral arteries and arterial stenoses. We believe the use of imaging methods described here will contribute substantially to the study of rodent cerebrovasculature. PMID:25985192

  13. Occurrence of a rhythmic slower wave in EMG prior to a rapid voluntary movement.

    PubMed

    Tanii, K

    1984-05-01

    The aim of the present study was to investigate whether an EMG slower wave prior to a rapid straightening-up movement is associated with motor preparation to perform the movement. The straightening movement was performed at 6 load intensities and under 3 conditions: without any external load; with an additional load; lifting a load. The subject could freely begin the rapid movement from a moderate forward-bending position whenever he was fully ready for the beginning of the movement after he held the bent posture. Bipolar surface EMGs of the erector spinal muscles at the L1 and L4 level, the gluteus maximus muscle and the semitendinosus muscle were led by a pair of skin electrodes with a time constant of 0.03 sec. The signal from the hip goniometer was measured simultaneously to identify the period of the movement. A distinct relationship between the occurrence of the slower wave and both load intensities and conditions was not found. However, the rhythmic slower wave often occurred in the muscles 200-450 msec before the movement. The occurrence of the wave in the muscles was often simultaneous. The signal from the hip goniometer did not change with the occurrence of the slower wave. The amplitude of the slower wave increased frequently. The present results suggest that the slower wave may reflect a significant change of motoneuronal activity in connection with motor preparation to perform the movement.

  14. Curvature reduces bending strains in the quokka femur

    PubMed Central

    McCabe, Kyle; Henderson, Keith; Pantinople, Jess; Milne, Nick

    2017-01-01

    This study explores how curvature in the quokka femur may help to reduce bending strain during locomotion. The quokka is a small wallaby, but the curvature of the femur and the muscles active during stance phase are similar to most quadrupedal mammals. Our hypothesis is that the action of hip extensor and ankle plantarflexor muscles during stance phase place cranial bending strains that act to reduce the caudal curvature of the femur. Knee extensors and biarticular muscles that span the femur longitudinally create caudal bending strains in the caudally curved (concave caudal side) bone. These opposing strains can balance each other and result in less strain on the bone. We test this idea by comparing the performance of a normally curved finite element model of the quokka femur to a digitally straightened version of the same bone. The normally curved model is indeed less strained than the straightened version. To further examine the relationship between curvature and the strains in the femoral models, we also tested an extra-curved and a reverse-curved version with the same loads. There appears to be a linear relationship between the curvature and the strains experienced by the models. These results demonstrate that longitudinal curvature in bones may be a manipulable mechanism whereby bone can induce a strain gradient to oppose strains induced by habitual loading. PMID:28348929

  15. Quantification of interaction and topological parameters of polyisoprene star polymers under good solvent conditions

    NASA Astrophysics Data System (ADS)

    Rai, Durgesh K.; Beaucage, Gregory; Ratkanthwar, Kedar; Beaucage, Peter; Ramachandran, Ramnath; Hadjichristidis, Nikos

    2016-05-01

    Mass fractal scaling, reflected in the mass fractal dimension df, is independently impacted by topology, reflected in the connectivity dimension c , and by tortuosity, reflected in the minimum dimension dmin. The mass fractal dimension is related to these other dimensions by df=c dmin . Branched fractal structures have a higher mass fractal dimension compared to linear structures due to a higher c , and extended structures have a lower dimension compared to convoluted self-avoiding and Gaussian walks due to a lower dmin. It is found, in this work, that macromolecules in thermodynamic equilibrium display a fixed mass fractal dimension df under good solvent conditions, regardless of chain topology. These equilibrium structures accommodate changes in chain topology such as branching c by a decrease in chain tortuosity dmin. Symmetric star polymers are used to understand the structure of complex macromolecular topologies. A recently published hybrid Unified scattering function accounts for interarm correlations in symmetric star polymers along with polymer-solvent interaction for chains of arbitrary scaling dimension. Dilute solutions of linear, three-arm and six-arm polyisoprene stars are studied under good solvent conditions in deuterated p -xylene. Reduced chain tortuosity can be viewed as steric straightening of the arms. Steric effects for star topologies are quantified, and it is found that steric straightening of arms is more significant for lower-molecular-weight arms. The observation of constant df is explained through a modification of Flory-Krigbaum theory for branched polymers.

  16. Comparison of Hero 642 and K3 rotary nickel-titanium files in curved canals of molars and a systematic review of the literature

    PubMed Central

    CAI, HUA-XIONG; CHENG, HUI-LING; SONG, JIE-WEN; CHEN, SU-YA

    2014-01-01

    The aim of the present study was to compare the root canal preparation ability of rotary nickel-titanium (NiTi) Hero 642 and K3 files in curved mandibular or maxillary molars. A total of 40 extracted mandibular molars with two separate mesial canals, an apical width of approximately size ≤15 and a root canal curvature of 15–30° were randomly divided into two groups and instrumented using Hero 642 (n=20) or K3 files (n=20). Canal straightening, working length, transportation, cross-sectional area, minimum dentin thickness and the canal angle curvature degree were examined, and a systematic review of the literature was conducted. No statistically significant differences were observed between the two groups with regard to the mean degree of straightening, mean change in working length, mean transportation, amount of dentin removed or remaining minimum dentin thickness (P>0.05). The canal angle curvature decreased in the two groups postoperatively. The systematic review identified six studies, and overall the two files performed similarly in the majority of categories examined. Therefore, the rotary NiTi Hero 642 and K3 files demonstrated comparable shaping abilities and maintenance of working length. PMID:25187795

  17. Numerical and theoretical study on the mechanism of biopolymer translocation process through a nano-pore

    NASA Astrophysics Data System (ADS)

    Alapati, Suresh; Fernandes, Dolfred Vijay; Suh, Yong Kweon

    2011-08-01

    We conducted a numerical study on the translocation of a biopolymer from the cis side to the trans side of a membrane through a synthetic nano-pore driven by an external electric field in the presence of hydrodynamic interactions (HIs). The motion of the polymer is simulated by 3D Langevin dynamics technique using a worm-like chain model of N identical beads, while HI between the polymer and fluid are incorporated by the lattice Boltzmann equation. The translocation process is induced by electrophoretic force, which sequentially straightens out the folds of the initial random configuration of the polymer chain on the cis side. Our simulation results on translocation time and velocity are in good quantitative agreement with the corresponding experimental ones when the surface charge on the nano-pore and the HI effect are considered explicitly. We found that the translocation velocity of each bead inside the nano-pore mainly depends upon the length of the straightened portion of the polymer in forced motion near the pore. We confirmed this by a theoretical formula. After performing simulations with different pore lengths, we observed that translocation velocity mainly depends upon the applied potential difference rather than upon the electric field inside the nano-pore.

  18. Shaping ability of reciprocating motion of WaveOne and HyFlex in moderate to severe curved canals: A comparative study with cone beam computed tomography

    PubMed Central

    Simpsy, Gurram Samuel; Sajjan, Girija S.; Mudunuri, Padmaja; Chittem, Jyothi; Prasanthi, Nalam N. V. D.; Balaga, Pankaj

    2016-01-01

    Introduction: M-Wire and reciprocating motion of WaveOne and controlled memory (CM) wire) of HyFlex were the recent innovations using thermal treatment. Therefore, a study was planned to evaluate the shaping ability of reciprocating motion of WaveOne and HyFlex using cone beam computed tomography (CBCT). Methodology: Forty-five freshly extracted mandibular teeth were selected and stored in saline until use. All teeth were scanned pre- and post-operatively using CBCT (Kodak 9000). All teeth were accessed and divided into three groups. (1) Group 1 (control n = 15): Instrumented with ProTaper. (2) Group 2 (n = 15): Instrumented with primary file (8%/25) WaveOne. (3) Group 3 (n = 15): Instrumented with (4%/25) HyFlex CM. Sections at 1, 3, and 5 mm were obtained from the pre- and post-operative scans. Measurement was done using CS3D software and Adobe Photoshop software. Apical transportation and degree of straightening were measured and statistically analyzed. Results: HyFlex showed lesser apical transportation when compared to other groups at 1 and 3 mm. WaveOne showed lesser degree of straightening when compared to other groups. Conclusion: This present study concluded that all systems could be employed in routine endodontics whereas HyFlex and WaveOne could be employed in severely curved canals. PMID:27994323

  19. Combustion Engineering, Inc. [LMFBR

    SciTech Connect

    Not Available

    1980-01-01

    Four (4) 3 '' O.D. x 0.470'' nominal wall thickness (NWT) hot rotary pierced/roll reduced modified AOD/ESR tube hollows were cold pilger reduced through one pass to 2'' O.D. x 0.250'' NWT tubing. Two (2) additional hollows of same size and process history were cold pilger reduced through one pass to 2 1/8'' O.D. x 0.200'' NWT. Six (6) 3 3/4'' O.D. x 0.600'' NWT hot extruded tube hollows were cold pilger reduced through two passes to 2'' O.D. x 0.250'' NWT tubing. Four of the extrusions represented duplex AOD/ESR melting practice and two extrusions represented AOD melting practice. Twelve (12) pieces of 2 1/8'' O.D. x 0.200'' NWT x approx. 9' long tubing were final heat treated, straightened, and ultrasonically tested. Twelve (12) more pieces of 2 1/8'' O.D. tubing have been solution austenitized (1177/sup 0/C) and are to be reaustenitized (1066/sup 0/C), tempered (760/sup 0/C), straightened, and ultrasonically inspected. All 2'' O.D. x 0.250'' NWT tubing is in the solution austenitized condition. Creep and stress rupture testing has continued on aged material from CarTech heat 91887 and on unaged material from CarTech heat 30182A.

  20. "Secondary stem lengthening" in the palm Iriartea deltoidea (Arecaceae) provides an efficient and novel method for height growth in a tree form.

    PubMed

    Renninger, Heidi J; Phillips, Nathan

    2012-04-01

    Although traditionally assumed that all height growth in trees occurs at apical meristems, sequential measurement of internode lengths in the palm Iriartea deltoidea suggested that stems were lengthening long after the differentiation of tissues and far below the apical meristem. This observation is difficult to reconcile with the fact that neither the water-conducting vessels nor the sugar-transporting sieve tube cells are capable of lengthening after differentiation. However, the vascular bundles in palms form a spiral within the stem and could theoretically lengthen if the spiral "straightened". We marked stretches of internodes on small and medium-sized palms and measured their lengths over 2 years. Additionally, we collected material from small palms with short internodes and large palms with long internodes and made cross sections to determine the angle of vascular bundles within stems. We found that stems lengthened (up to 12% over 2 years) below the apical meristem in small and medium-sized palms and that the spiral angle in vascular bundles of small palms was significantly larger than at the base of large palms indicating a straightening of the spiral. These results represent the first determination of "secondary lengthening" in tree stems as well as the most efficient method for height growth in terms of carbon investment. Likewise, elongation of stems allows palms to exhibit plasticity in height growth rates for more rapid growth when short-lived canopy gaps are present than they would have with apical growth alone.

  1. How Cellulose Stretches: Synergism between Covalent and Hydrogen Bonding

    PubMed Central

    2014-01-01

    Cellulose is the most familiar and most abundant strong biopolymer, but the reasons for its outstanding mechanical performance are not well understood. Each glucose unit in a cellulose chain is joined to the next by a covalent C–O–C linkage flanked by two hydrogen bonds. This geometry suggests some form of cooperativity between covalent and hydrogen bonding. Using infrared spectroscopy and X-ray diffraction, we show that mechanical tension straightens out the zigzag conformation of the cellulose chain, with each glucose unit pivoting around a fulcrum at either end. Straightening the chain leads to a small increase in its length and is resisted by one of the flanking hydrogen bonds. This constitutes a simple form of molecular leverage with the covalent structure providing the fulcrum and gives the hydrogen bond an unexpectedly amplified effect on the tensile stiffness of the chain. The principle of molecular leverage can be directly applied to certain other carbohydrate polymers, including the animal polysaccharide chitin. Related but more complex effects are possible in some proteins and nucleic acids. The stiffening of cellulose by this mechanism is, however, in complete contrast to the way in which hydrogen bonding provides toughness combined with extensibility in protein materials like spider silk. PMID:24568640

  2. How cellulose stretches: synergism between covalent and hydrogen bonding.

    PubMed

    Altaner, Clemens M; Thomas, Lynne H; Fernandes, Anwesha N; Jarvis, Michael C

    2014-03-10

    Cellulose is the most familiar and most abundant strong biopolymer, but the reasons for its outstanding mechanical performance are not well understood. Each glucose unit in a cellulose chain is joined to the next by a covalent C-O-C linkage flanked by two hydrogen bonds. This geometry suggests some form of cooperativity between covalent and hydrogen bonding. Using infrared spectroscopy and X-ray diffraction, we show that mechanical tension straightens out the zigzag conformation of the cellulose chain, with each glucose unit pivoting around a fulcrum at either end. Straightening the chain leads to a small increase in its length and is resisted by one of the flanking hydrogen bonds. This constitutes a simple form of molecular leverage with the covalent structure providing the fulcrum and gives the hydrogen bond an unexpectedly amplified effect on the tensile stiffness of the chain. The principle of molecular leverage can be directly applied to certain other carbohydrate polymers, including the animal polysaccharide chitin. Related but more complex effects are possible in some proteins and nucleic acids. The stiffening of cellulose by this mechanism is, however, in complete contrast to the way in which hydrogen bonding provides toughness combined with extensibility in protein materials like spider silk.

  3. Ho:YAG laser in reshaping tracheal cartilage: a pilot investigation using ex vivo porcine and rabbit cartilage

    NASA Astrophysics Data System (ADS)

    Lam, Anthony; Protsenko, Dmitry E.; Carbone, Nicholas; Li, Chao; Jackson, Ryan; Wong, Brian J.

    2004-07-01

    Stenotic, collapsed, and flow-restricted tracheal airways may result from blunt trauma, chronic infection, and the prolonged endotracheal intubation. This pilot investigation characterizes the degree of shape change produced by Ho:YAG laser (λ=2.12 μm) irradiation of rabbit and pig trachea tissue as a function of laser dosimetry and application protocol. Force displacement curves were generated using fresh lagomorph and porcine tracheal cartilage rings secured in a modified single beam cantilever geometry. These specimens were then irradiated for varying amounts of time and power with the objective of straightening these curved specimens. The degree of shape change was documented photographically. Force and surface temperature were monitored. Confocal microscopy was then used in combination a vital staine ("live-dead assay") to determine the level of viability of straightened cartilage for selected exposure time-power pairs. Laser Cartilage Reshaping of the trachea may provide a new method to treat severe tracheal injuries without the need for classic open surgical techniques. This pilot investigation is the first step toward demonstrating the feasibility of this technique. Long-term, the design of stents combined with laser irradiation may provide a means to alter tracheal shape.

  4. Ex Vivo Comparison of Mtwo and RaCe Rotary File Systems in Root Canal Deviation: One File Only versus the Conventional Method.

    PubMed

    Aminsobhani, Mohsen; Razmi, Hasan; Nozari, Solmaz

    2015-07-01

    Cleaning and shaping of the root canal system is an important step in endodontic therapy. New instruments incorporate new preparation techniques that can improve the efficacy of cleaning and shaping. The aim of this study was to compare the efficacy of Mtwo and RaCe rotary file systems in straightening the canal curvature using only one file or the conventional method. Sixty mesial roots of extracted human mandibular molars were prepared by RaCe and Mtwo nickel-titanium (NiTi) rotary files using the conventional and only one rotary file methods. The working length was 18 mm and the curvatures of the root canals were between 15-45°. By superimposing x-ray images before and after the instrumentation, deviation of the canals was assessed using Adobe Photoshop CS3 software. Preparation time was recorded. Data were analyzed using three-way ANOVA and Tukey's post hoc test. There were no significant differences between RaCe and Mtwo or between the two root canal preparation methods in root canal deviation in buccolingual and mesiodistal radiographs (P>0.05). Changes of root canal curvature in >35° subgroups were significantly more than in other subgroups with smaller canal curvatures. Preparation time was shorter in one file only technique. According to the results, the two rotary systems and the two root canal preparation methods had equal efficacy in straightening the canals; but the preparation time was shorter in one file only group.

  5. Relaxation of bending stresses and the reversibility of residual stresses in amorphous soft magnetic alloys

    SciTech Connect

    Kekalo, I. B.; Mogil’nikov, P. S.

    2015-06-15

    The reversibility of residual bending stresses is revealed in ribbon samples of cobalt- and iron-based amorphous alloys Co{sub 69}Fe{sub 3.7}Cr{sub 3.8}Si{sub 12.5}B{sub 11} and Fe{sub 57}Co{sub 31}Si{sub 2.9}B{sub 9.1}: the ribbons that are free of applied stresses and bent under the action of residual stresses become completely or incompletely straight upon annealing at the initial temperatures. The influence of annealing on the relaxation of bending stresses is studied. Preliminary annealing is found to sharply decrease the relaxation rate of bending stresses, and the initial stage of fast relaxation of these stresses is absent. Complete straightening of preliminarily annealed ribbons is shown to occur at significantly higher temperatures than that of the initial ribbons. Incomplete straightening of the ribbons is explained by the fact that bending stresses relaxation at high annealing temperatures proceeds due to both reversible anelastic deformation and viscous flow, which is a fully irreversible process. Incomplete reversibility is also caused by irreversible processes, such as the release of excess free volume and clustering (detected by small-angle X-ray scattering). The revealed differences in the relaxation processes that occur in the cobalt- and iron-based amorphous alloys are discussed in terms of different atomic diffusion mobilities in these alloys.

  6. Gravitropism of axial organs in multicellular plants.

    PubMed

    Kutschera, U

    2001-01-01

    Gravitropism of plant organs such as roots, stems and coleoptiles can be separated into four distinct phases: 1. perception (gravity sensing), 2. transduction of a signal into the target region and 3. the response (differential growth). This last reaction is followed by a straightening of the curved organ (4.). The perception of the gravitropic stimulus upon horizontal positioning of the organ (1.) occurs via amyloplasts that sediment within the statocytes. This conclusion is supported by our finding that submerged rice coleoptiles that lack sedimentable amyloplasts show no graviresponse. The mode of signal transduction (2.) from the statocytes to the peripheral cell layers is still unknown. Differential growth (3.) consists of a cessation of cell expansion on the upper side and an enhancement of elongation on the lower side of the organ. Based on the facts that the sturdy outer epidermal wall (OEW) constitutes the growth-controlling structure of the coleoptile and that growth-related osmiophilic particles accumulate on the upper OEW, it is concluded that the differential incorporation of wall material (presumably glycoproteins) is causally involved. During gravitropic bending, electron-dense particles ('wall-loosening capacity') accumulate on the growth-inhibited upper OEW. It is proposed that the autotropic straightening response, which is in part due to an acceleration of cell elongation on the curved upper side, may be attributable to an incorporation of the accumulated particles ('release of wall-loosening capacity'). This novel mechanism of autotropic re-bending and its implications for the Cholodny-Went hypothesis are discussed.

  7. Minimally invasive scoliosis treatment with a Ho:YAG laser

    NASA Astrophysics Data System (ADS)

    Rumpf, Christian G.; Lang, Robert D.; Goetz, Marcus H.

    2000-11-01

    Today most surgical treatment of spinal deformations is concentrated on invasive mechanical techniques with long operation times and major effects on the patient's mobility. The proposed minimally invasive technique using laser light for tissue ablation offers a possibility of gentle scoliosis treatment. It is thought that an early removal of the epiphysial growth zone on the convex side over several vertebrae results in a straightening of the spine. In a first evaluation, four different laser systems including argon ion, Nd:YAG (Q-switched), Nd:YAG (cw), and Ho:YAG laser were compared with respect to thermal damage to adjacent tissue, ablation rates, efficiency and laser handling. For in-vivo investigation, fresh lamb spine was used. Comparison showed that the Ho:YAG laser is the most appropriate laser for the given goal, providing efficient photoablation with moderate thermal effects on the adjacent tissue. In a second step the proposed minimally invasive operation technique was performed in in-vivo experiments on young foxhounds using 3D- thoracoscopic operation techniques. During these operations temperature mapping was done using fiber-optic fluorescent probes. After 12 months of normal growth the animals were sacrificed and x-ray as well as MRI was performed on the spine. First results show a positive effect of scoliotic growth in two cases. Being able to produce a scoliosis by hemiepiphysiodesis on the vertebra, It is thought that this technique is successful for a straightening of the spine on patients with scoliosis.

  8. Self-propelling microswimmer made of a bi-faced hydrogel

    NASA Astrophysics Data System (ADS)

    Alexeev, Alexander; Nikolov, Svetoslav V.; Yeh, Peter

    2014-03-01

    We use dissipative particle dynamics to design a new self-propelling microswimmer. Our microswimmer features a simple design and represents an X-shaped gel layer. The gel has two distinct sides or facets: one facet is responsive and swells when an external stimulus is applied, whereas the other facet is passive. We show that when an external stimulus is applied periodically, the swimmer propels itself unidirectionally in a highly viscous fluid. The propulsion is associated with periodic shape changes. When the stimulus is applied, the responsive facet swells, inducing internal stresses in the gel causing both lateral expansion and bending of the microswimmer. When the external stimulus is removed, the responsive layer contracts, and elastic forces cause the microswimmer to straighten and to recover the initial shape. The combination of the sequential expansion, bending, contraction, and straightening produces a time irreversible motion pattern leading to net propulsion at low Reynolds number. We examine how the swimming speed can be enhanced by selecting material properties and geometry of the swimmer. This work is supported by NSF CAREER award DMR-1255288.

  9. Pike Esox Lucius Distribution and Feeding Comparisons in Natural and Historically Channelized River Sections

    NASA Astrophysics Data System (ADS)

    Ivanovs, Kaspars

    2016-12-01

    During the last century a large portion of small and medium-sized rivers in Latvia were channelized, hydroelectric power stations were also built, which led to changes in the hydrodynamic conditions, geomorphological structure, as well as a change in the fish fauna. Fish are an integral part of any community in natural or man-made bodies of water. They actively participate in maintaining the system, balancing/equilibrium, energy, substance transformation and biomass production. They are able to influence other organisms in the ecosystem in which they live. The aim of the paper "Pike distribution and feeding comparisons in natural and historically channelized river sections" is to find out what pike feed on in different environments in Latvian rivers, such as natural and straightened river sections, as well as what main factors determine the composition of their food. Several points were assessed during the course of the study: the impact of environmental conditions on the feeding habits and the distribution of pike; the general feeding habits of predators in Latvian rivers; the feeding differences of predators in natural and straightened river sections; and lastly, rhithral and pothamal habitats were compared. The study was based on data from 2014 and 2015 on fish fauna monitoring. During the study, 347 pike were collected from 136 plots using electrofishing method.

  10. Low-relief landscape modeling with human activities

    NASA Astrophysics Data System (ADS)

    Yan, Q.; Kumar, P.; Anders, A. M.

    2015-12-01

    Intensively managed landscapes (IMLs) in the Midwestern United States have been shaped by repeated glacial events over geologic time scales followed by rapid human modifications for agriculture and artificial drainage that were overlaid on extremely low gradient stream networks. These landscapes are heavily modified by agriculture, artificial drainage, deforestation, urbanization, and wetland destruction. Channel head extension and periodic dredging for channel straightening not only strongly affected hydrologic and geomorphologic response, but also fundamentally alter the energy consumption in the whole river basin. However, it is unclear how the landscape consumes and responds to the extra energy from human activities. Therefore, we evaluate the present-day dynamics of river network from the perspective of of geomorphic equilibrium, hydrological response, and the rate of energy dissipation. Then, we simulate the landscape evolution to discover the tendency of the system. We find that channel head extension and straightening increases the rate of energy dissipation and pushes the river network further away from equilibrium condition. From our numerical model simulation, extending and maintaining the ditches in the river network can cause large ridge migration, river network redistribution, and enlargement of the drainage basin area. Our research demonstrates how the river basin responds to human activities in glaciated landscape, and how it is likely to behave with artificial modifications on the topography in the future. We attribute the legacy to drainage basin reorganization and theorized that humans can have a lasting impact on the landscape even after active management has ceased.

  11. Design and prototyping of a large capacity high frequency pulse tube

    NASA Astrophysics Data System (ADS)

    Ercolani, E.; Poncet, J. M.; Charles, I.; Duband, L.; Tanchon, J.; Trollier, T.; Ravex, A.

    2008-09-01

    This document describes the design and the prototyping performed at CEA/SBT in partnership with AIR LIQUIDE of a high frequency large cooling power pulse tube. Driven at 58 Hz by a 7.5 kW flexure bearing pressure wave generator, this system provides a net heat lift of 210 W at 65 K. The phase shift is obtained by an inertance and a buffer volume. This type of cryogenic cooler can be used for on site gas liquefaction or drilling site and for high temperature superconductivity power device cooling (transmission lines, large generators, fault current limiters). In this paper, we focus on two essential points, the regenerator and the flow straightener. The regenerator is a key component for good performance of the pulse tube cooler. It must have a large thermal inertia, a low dead volume, a good heat transfer gas/matrix and at the same time, small pressure drop. In the present case and unlike typical moderate cooling power pulse tubes, the regenerator is very compact. However, the resulting conductive losses remain negligible compared to the cooling power targeted. The goal of the flow straightener is to avoid as much as possible any jet stream effect and to guarantee the uniformity of the velocity field at both ends of the pulse tube. Indeed multi-dimensional flow effects can significantly impact the performances of the machine.

  12. Hypospadias. A review of 299 cases operated 1957-69.

    PubMed

    Johanson, B; Avellán, L

    1980-01-01

    A review of 299 unselected primary cases of hypospadias of all types treated during the period 1957 to 1969 is presented. The same indications for operation and the same surgical principles were applied in all cases. The surgical treatment was performed in two stages: meatotomy or meatotomy combined with straightening in the first stage and urethral construction according to Denis Browne's method in the second stage. Complications occurred after the urethral construction in 11/289 cases (separation of the skin flaps in 5/289 and fistulas in 6/289). All 11 patients were reoperated with fully satisfactory results. The long-term results were followed up in a series of 220/299 cases. This series was used to study different problems affecting hypospadias. The mean age at the first operation was 8.5 years and the median age 4.4. The mean age at the latest control was 15.1 years and the median age 18.4. At the latest control no relapses with regard to curvature were observed during erection in the 151/220 cases in which straightening was performed. The meatus was adequate in all cases and the urinary flow, measured with a uroflowmeter, was normal.

  13. Catapult effect in pole vaulting: is muscle coordination determinant?

    PubMed

    Frère, Julien; Göpfert, Beat; Hug, François; Slawinski, Jean; Tourny-Chollet, Claire

    2012-02-01

    This study focused on the phase between the time of straightened pole and the maximum height (HP) of vaulter and aimed at determining the catapult effect in pole vaulting on HP. Seven experienced vaulters performed 5-10 vaults recorded by two video cameras, while the surface electromyography (sEMG) activity of 10 upper limbs muscles was recorded. HP was compared with an estimated maximum height (HP(est)) allowing the computation of a push-off index. Muscle synergies were extracted from the sEMG activity profiles using a non-negative matrix factorization algorithm. No significant difference (p>0.47) was found between HP(est) (4.64±0.21m) and HP (4.69±0.23m). Despite a high inter-individual variability in sEMG profiles, two muscle synergies were extracted for all the subjects which accounted for 96.1±2.9% of the total variance. While, the synergy activation coefficients were very similar across subjects, a higher variability was found in the muscle synergy vectors. Consequently, whatever the push-off index among the pole vaulters, the athletes used different muscle groupings (i.e., muscle synergy vectors) which were activated in a similar fashion (i.e., synergy activation coefficients). Overall, these results suggested that muscle coordination adopted between the time of straightened pole and the maximum height does not have a major influence on HP.

  14. Numerical and theoretical study on the mechanism of biopolymer translocation process through a nano-pore.

    PubMed

    Alapati, Suresh; Fernandes, Dolfred Vijay; Suh, Yong Kweon

    2011-08-07

    We conducted a numerical study on the translocation of a biopolymer from the cis side to the trans side of a membrane through a synthetic nano-pore driven by an external electric field in the presence of hydrodynamic interactions (HIs). The motion of the polymer is simulated by 3D Langevin dynamics technique using a worm-like chain model of N identical beads, while HI between the polymer and fluid are incorporated by the lattice Boltzmann equation. The translocation process is induced by electrophoretic force, which sequentially straightens out the folds of the initial random configuration of the polymer chain on the cis side. Our simulation results on translocation time and velocity are in good quantitative agreement with the corresponding experimental ones when the surface charge on the nano-pore and the HI effect are considered explicitly. We found that the translocation velocity of each bead inside the nano-pore mainly depends upon the length of the straightened portion of the polymer in forced motion near the pore. We confirmed this by a theoretical formula. After performing simulations with different pore lengths, we observed that translocation velocity mainly depends upon the applied potential difference rather than upon the electric field inside the nano-pore.

  15. Measuring Outdoor Air Intake Rates into Existing Building

    SciTech Connect

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2009-04-16

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  16. Characterization of stainless steel 304 tubing

    SciTech Connect

    Sunwoo, A.J.; Brooks, M.A.; Kervin, J.E.

    1995-10-16

    Earlier studies have shown that stainless steel 304 (SS304) containing martensite is susceptible to hydrogen embrittlement. This generated concern regarding the structural integrity of SS304 tubing we use in the W87 pit tube. During surveillance operations, the pit tube undergoes a series of bending and straightening as it goes through a number of surveillance cycles. This motivated the study to characterize austenitic SS304 tubing obtained from Rocky Flats. The tubes continued to display structural soundness even after numerous repeated bending and straightening cycles. The minimum and maximum number of bends to failure occurred after 13 and 16 cycles, respectively. After 5 bends, both the inner and outer surfaces of the tubing showed no microcracks. When the bent tubing samples were pressurized and tested using deuterium at 74{degrees}C and at {approximately}78{degrees}C, they failed away from the bent area. Thus deuterium embrittlement of the bent SS304 tubing should not be a problem. Moreover, to increase our 95% confidence level to 5 bends, we are planning to perform at least four additional bends to failure tests.

  17. A review of surgical strategies for penile prosthesis implantation in patients with Peyronie's disease.

    PubMed

    Anaissie, James; Yafi, Faysal A

    2016-06-01

    The introduction of the inflatable penile prosthesis (IPP) has revolutionized the treatment of patients with both Peyronie's disease (PD) and erectile dysfunction (ED). A thorough literature review was performed in order to review the surgical strategies used to treat PD, using the PubMed online database with the keywords "penile prosthesis", "surgical management" and "Peyronie's disease". Patient satisfaction rates of 72-100% and partner satisfaction rates of 89% have been reported in the literature, although strong preoperative education may be needed to prepare patients for risks such as penile shortening, seen in up to 54% of patients. Three-piece IPPs are most commonly used, and when comparing the two most popular models (AMS 700 CX vs. Coloplast Titan), no significant differences were seen in functional outcomes or patient satisfaction. Simple insertion of an IPP has been shown to resolve curvature in 33-90% of patients, but surgeons may often need to also utilize ancillary straightening procedures for residual curvatures. Manual modeling can correct residual curvature with an 86-100% success rate, but with a 4% risk of urethral injury. When the post-modeling residual curvature exceeds 30 degrees, a plaque-releasing incision or plication is recommended to further reduce curvature. Grafting is recommended if the resulting incisional defect is larger than two centimeters. Alternative straightening techniques such as plication prior to IPP insertion, endoscopic plaque resection, the "scratch technique" and bone saw plaque incision have also been described.

  18. Automated identification of best-quality coronary artery segments from multiple-phase coronary CT angiography (cCTA) for vessel analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Chuan; Chan, Heang-Ping; Hadjiiski, Lubomir M.; Chughtai, Aamer; Wei, Jun; Kazerooni, Ella A.

    2016-03-01

    We are developing an automated method to identify the best quality segment among the corresponding segments in multiple-phase cCTA. The coronary artery trees are automatically extracted from different cCTA phases using our multi-scale vessel segmentation and tracking method. An automated registration method is then used to align the multiple-phase artery trees. The corresponding coronary artery segments are identified in the registered vessel trees and are straightened by curved planar reformation (CPR). Four features are extracted from each segment in each phase as quality indicators in the original CT volume and the straightened CPR volume. Each quality indicator is used as a voting classifier to vote the corresponding segments. A newly designed weighted voting ensemble (WVE) classifier is finally used to determine the best-quality coronary segment. An observer preference study is conducted with three readers to visually rate the quality of the vessels in 1 to 6 rankings. Six and 10 cCTA cases are used as training and test set in this preliminary study. For the 10 test cases, the agreement between automatically identified best-quality (AI-BQ) segments and radiologist's top 2 rankings is 79.7%, and between AI-BQ and the other two readers are 74.8% and 83.7%, respectively. The results demonstrated that the performance of our automated method was comparable to those of experienced readers for identification of the best-quality coronary segments.

  19. Spectrofluorescent characterization of changes in hair chemistry induced by environmental stresses.

    PubMed

    McMullen, Roger L; Chen, Susan; Moore, David J

    2011-01-01

    Hair is frequently exposed to environmental stresses and chemical insults that result in damage to its internal structure and its outer cuticular components. Spectrofluorescence is a useful tool to monitor the health of biological tissues as it can measure the level of tryptophan (Trp), which is representative of protein integrity. In addition to Trp fluorescence, several other fluorophores are also present in hair and are believed to be attributed to kynurenenine, N-formylkynurenine, and 3-hydroxykynurenine, which are known metabolic and degradation products of Trp that are affected by environmental stresses normally experienced by hair. In this work, we were able to construct an endogenous fingerprint of fluorescent compounds present in hair by employing a range of excitation wavelengths from 270 nm to 450 nm with a resolution of 2 nm. As a result, we generated surface plots of fluorescence emission as a function of excitation and emission wavelengths (excitation-emission matrices). Thus, we were able to profile the levels of various structural molecules in hair before and after exposure to UV irradiation and thermal straightening irons as well as to chemical treatment such as bleaching and straightening.

  20. Curvature reduces bending strains in the quokka femur.

    PubMed

    McCabe, Kyle; Henderson, Keith; Pantinople, Jess; Richards, Hazel L; Milne, Nick

    2017-01-01

    This study explores how curvature in the quokka femur may help to reduce bending strain during locomotion. The quokka is a small wallaby, but the curvature of the femur and the muscles active during stance phase are similar to most quadrupedal mammals. Our hypothesis is that the action of hip extensor and ankle plantarflexor muscles during stance phase place cranial bending strains that act to reduce the caudal curvature of the femur. Knee extensors and biarticular muscles that span the femur longitudinally create caudal bending strains in the caudally curved (concave caudal side) bone. These opposing strains can balance each other and result in less strain on the bone. We test this idea by comparing the performance of a normally curved finite element model of the quokka femur to a digitally straightened version of the same bone. The normally curved model is indeed less strained than the straightened version. To further examine the relationship between curvature and the strains in the femoral models, we also tested an extra-curved and a reverse-curved version with the same loads. There appears to be a linear relationship between the curvature and the strains experienced by the models. These results demonstrate that longitudinal curvature in bones may be a manipulable mechanism whereby bone can induce a strain gradient to oppose strains induced by habitual loading.

  1. Stabilization of electrical sensing properties of carbon fiber sensors using pre-tensioning approach

    NASA Astrophysics Data System (ADS)

    Saifeldeen, M. A.; Fouad, N.; Huang, H.; Wu, Z. S.

    2017-01-01

    Owing to fabrication defects in carbon fiber (CF) tows, the unevenness of fiber roves, such as local bends, misalignments, and skewness, results in irregular distribution of the electrical resistance in the transverse direction along the gauge length of a sensor, which affects its performance. In this study, a pre-tension approach was developed according to the creep mechanism of composites to straighten the CFs. In addition, the resin relaxation was controlled by tensioning the fibers during and after hardening of the epoxy resin using a double-tension method to enhance the electrical sensing properties of long gauge carbon fiber line (CFL) strain sensors. Different levels of sustained tensile stresses were studied to obtain the optimal tensile stress level both during and after hardening to be applied in the double-tension method. The results of static and dynamic tests showed that the double-tension technique could significantly straighten the fibers, and stabilize the transverse connections of CFL sensors in the case of tensioning the fibers during and after hardening under a sustained stress of 60% of the ultimate tensile stress of the CFs. The proposed double-tension method was utilized to improve the response of the CFL sensors with short gauge lengths.

  2. Generating hand dysaesthesiae: the “GHD phenomenon” – straight to the diagnosis

    PubMed Central

    Lonergan, Roisin; Gorman, Grainne; Alexander, Michael D; Killeen, Ronan; de Blacam, Catherine; Tubridy, Niall

    2009-01-01

    Two Irish women presented with difficulty in completion of hair straightening, limited by upper limb dysaesthesiae due to claudication or brachial plexus entrapment induced by sustained shoulder abduction beyond 90 degrees. The first described arm pain precipitated by elevation and sustained abduction above shoulder level, particularly while using her GHD hair-straightener. Elevated arm stress test was positive and a left cervical rib was seen on chest x ray. Neurogenic thoracic outlet syndrome (TOS) was diagnosed and the cervical rib was resected. The second described arm tingling and weakness when performing tasks involving shoulder abduction and elevation, limiting GHD use to 10 min before having to rest. Upper limb blood pressure and pulses were undetectable. Erythrocyte sedimentation rate was elevated and flow on radial Doppler disappeared on abduction and elevation of each arm. A CT pulmonary angiography demonstrated features of Takayasu’s arteritis. Vascular TOS was diagnosed. Symptoms resolved with corticosteroids, followed by long-term immunosuppression and anti-coagulation. PMID:21686996

  3. Comparison of root canal preparation using RaCe and ProTaper rotary Ni-Ti instruments.

    PubMed

    Paqué, F; Musch, U; Hülsmann, M

    2005-01-01

    To compare various parameters of root canal preparation using RaCe (FKG Dentaire, La-Chaux-de-Fonds, Switzerland) and ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) nickel-titanium (Ni-Ti) instruments. Fifty extracted mandibular molars with mesial root canal curvatures between 20 degrees and 40 degrees were embedded in a muffle system. All root canals were prepared to size 30 using RaCe or ProTaper rotary instruments in low-torque motors with torque control and constant speed of 300 r.p.m. (ProTaper with ATR Tecnika, Advanced Technology Research, Pistoia, Italy; RaCe with EndoStepper, S.E.T., Olching, Germany). In both groups irrigation was performed with 2 mL NaOCl (3%) after each instrument size. Calcinase-Slide (lege artis, Dettenhausen, Germany) was used as a chelating agent with each instrument. The following parameters were evaluated: straightening of curved root canals, postoperative root canal cross-sections, safety issues and working time. Cleanliness of the root canal walls was investigated under the SEM using 5-score indices for debris and smear layer. Statistical analysis was performed using the following tests: Wilcoxon's test for straightening and working time was used (P < 0.05); Fisher's exact test for comparison of cross-sections and root canal cleanliness (P < 0.05). Both Ni-Ti systems maintained curvature well; the mean degree of straightening was less than 1 degrees for both systems. Following preparation with RaCe, 49% of the root canals had a round or oval diameter and 50% an irregular diameter, ProTaper preparations resulted in a round or oval diameter in 50% of the cases. For debris, RaCe and ProTaper achieved 47 and 49% scores of 1 and 2, respectively; there was no significant difference. For smear layer, RaCe and ProTaper achieved 51 and 33% scores 1 and 2, respectively; no statistically significant differences were apparent for the coronal and middle sections of the root canals, but RaCe performed significantly better in the

  4. Effect of rotational speed on root canal preparation with Hero 642 rotary Ni-Ti instruments.

    PubMed

    Karagöz-Küçükay, Işil; Ersev, Handan; Engin-Akkoca, Ece; Küçükay, Sedat; Gürsoy, Tankut

    2003-07-01

    The purpose of this study was to evaluate the influence of Hero 642 rotary Ni-Ti instruments driven at 300, 400, or 600 rpm on root canal straightening, loss of working length, and instrument breakage. Sixty mesial root canals from extracted human mandibular molars were divided into 3 groups of 20 each and were instrumented at the aforementioned rotational speeds with a crown-down technique. Using a digital intraoral radiography system directly on the images of pre- and postoperative radiographs, degrees of canal curvatures were measured and recorded. Statistical analysis showed that final canal curvatures and working lengths were significantly reduced compared with those of original values in each group (p < 0.001). However, using Hero 642 rotary Ni-Ti system at different rotational speeds had no effect on canal curvature and working length alterations (p > 0.05). No file breakage was observed in any of the groups.

  5. On the tear resistance of skin

    DOE PAGES

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; ...

    2015-03-27

    Tear resistance is vitally important for the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. Here we explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. Finally, we express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensilemore » direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.« less

  6. On the tear resistance of skin

    SciTech Connect

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-03-27

    Tear resistance is vitally important for the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. Here we explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. Finally, we express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.

  7. Spines of Steel: A Case of Surgical Enthusiasm in Cold War America.

    PubMed

    Linker, Beth

    2016-01-01

    Just as the prevalence of scoliosis began to decline precipitously after World War II, American orthopedic surgeon Dr. Paul R. Harrington devised a new, invasive surgical system whereby implantable prosthetic metal rods and hooks were used to straighten curved backs. By the 1970s, "Harrington rods" had become the gold standard of surgical scoliosis care in the United States, replacing more conventional methods of exercise, bracing, and casting. This article situates the success of Harrington rods within a much larger and historically longer debate about why, when compared to those in other nations, American surgeons appear to be "more aggressive" and "knife-happy." Using Harrington's papers and correspondence, I argue that patients played a vital role in the rise of spinal surgery. As such, this article examines not only how surgical enthusiasm has been historically measured, defined, and morally evaluated, but also how scoliosis became classified as a debility in need of surgical management.

  8. NASA Benefits Earth

    NASA Technical Reports Server (NTRS)

    Robinson, Julie A.

    2009-01-01

    This slide presentation reviews several ways in which NASA research has benefited Earth and made life on Earth better. These innovations include: solar panels, recycled pavement, thermometer pill, invisible braces for straightening teeth, LASIK, aerodynamic helmets and tires for bicycles, cataract detection, technology that was used to remove Anthrax spores from mail handling facilities, study of atomic oxygen erosion of materials has informed the restoration of artwork, macroencapsulation (a potential mechanism to deliver anti cancer drugs to specific sites), and research on a salmonella vaccine. With research on the International Space Station just beginning, there will be opportunities for entrepreneurs and other government agencies to access space for their research and development. As well as NASA continuing its own research on human health and technology development.

  9. Cervical spine injuries in football players.

    PubMed

    Thomas, B E; McCullen, G M; Yuan, H A

    1999-01-01

    Cervical spine injuries have been estimated to occur in 10% to 15% of football players, most commonly in linemen, defensive ends, and linebackers. The overwhelming majority of such injuries are self-limited, and full recovery can be expected. However, the presenting symptoms of serious cervical spine injuries may closely resemble those of minor injuries. The orthopaedic surgeon frequently must make a judgment, on the field or later in the office, about the advisability of returning the athlete to the game. These decisions can have an enormous impact on the player and his family. Most severe cervical spine injuries share the common mechanism of application of an axial load to the straightened spine. Avoiding techniques that employ head-down "spear" tackling and wearing properly fitted equipment markedly reduce the risk of serious injury.

  10. StoryFlow: tracking the evolution of stories.

    PubMed

    Liu, Shixia; Wu, Yingcai; Wei, Enxun; Liu, Mengchen; Liu, Yang

    2013-12-01

    Storyline visualizations, which are useful in many applications, aim to illustrate the dynamic relationships between entities in a story. However, the growing complexity and scalability of stories pose great challenges for existing approaches. In this paper, we propose an efficient optimization approach to generating an aesthetically appealing storyline visualization, which effectively handles the hierarchical relationships between entities over time. The approach formulates the storyline layout as a novel hybrid optimization approach that combines discrete and continuous optimization. The discrete method generates an initial layout through the ordering and alignment of entities, and the continuous method optimizes the initial layout to produce the optimal one. The efficient approach makes real-time interactions (e.g., bundling and straightening) possible, thus enabling users to better understand and track how the story evolves. Experiments and case studies are conducted to demonstrate the effectiveness and usefulness of the optimization approach.

  11. Weld bead reinforcement removal: A method of improving the strength and ductility of peaked welds in 2219-T87 aluminum alloy plate

    NASA Technical Reports Server (NTRS)

    Lovoy, C. V.

    1979-01-01

    The results of a study to determine the degree to which the ductility and tensile properties of peaked welds could be enhanced by removing the reinforcing bead and fairing the weld nugget into the adjacent parent metal are presented. The study employed 2219-T87 aluminum alloy plate, tungsten inert gas (TIG) welding, and 2319 filler wire. The study concluded that significant improvements in peak weld, ultimate strength, and ductility can be obtained through removal and fairing of the weld reinforcing bead. The specimens so treated and tested in this program exhibited ultimate strength improvements of 2 to 3 percent for peak angles of 5.8 to 10 degrees and 10 to 22 percent for welds with peak angles of 11.7 to 16.9 degrees. It was also determined that removal of the weld bead enhanced the ability of peaked welds to straighten when exposed to cyclic loading at stress levels above the yield strength.

  12. Functions of plant-specific myosin XI: from intracellular motility to plant postures.

    PubMed

    Ueda, Haruko; Tamura, Kentaro; Hara-Nishimura, Ikuko

    2015-12-01

    The plant-specific protein motor class myosin XI is known to function in rapid bulk flow of the cytoplasm (cytoplasmic streaming) and in organellar movements. Recent studies unveiled a wide range of physiological functions of myosin XI motors, from intracellular motility to organ movements. Arabidopsis thaliana has 13 members of myosin XI class. In vegetative organs, myosins XIk, XI1, and XI2 primarily contribute to dynamics and spatial configurations of endoplasmic reticulum that develops a tubular network in the cell periphery and thick strand-like structures in the inner cell regions. Myosin XI-i forms a nucleocytoplasmic linker and is responsible for nuclear movement and shape. In addition to these intracellular functions, myosin XIf together with myosin XIk is involved in the fundamental nature of plants; the actin-myosin XI cytoskeleton regulates organ straightening to adjust plant posture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Quasi-periodic solutions of the Belov-Chaltikian lattice hierarchy

    NASA Astrophysics Data System (ADS)

    Geng, Xianguo; Zeng, Xin

    Utilizing the characteristic polynomial of Lax matrix for the Belov-Chaltikian (BC) lattice hierarchy associated with a 3 × 3 discrete matrix spectral problem, we introduce a trigonal curve with three infinite points, from which we establish the associated Dubrovin-type equations. The essential properties of the Baker-Akhiezer function and the meromorphic function are discussed, that include their asymptotic behavior near three infinite points on the trigonal curve and the divisor of the meromorphic function. The Abel map is introduced to straighten out the continuous flow and the discrete flow in the Jacobian variety, from which the quasi-periodic solutions of the entire BC lattice hierarchy are obtained in terms of the Riemann theta function.

  14. Direct contact, binary fluid geothermal boiler

    DOEpatents

    Rapier, P.M.

    1979-12-27

    Energy is extracted from geothermal brines by direct contact with a working fluid such as isobutane which is immiscible with the brine in a geothermal boiler. The geothermal boiler provides a distributor arrangement which efficiently contacts geothermal brine with the isobutane in order to prevent the entrainment of geothermal brine in the isobutane vapor which is directed to a turbine. Accordingly the problem of brine carryover through the turbine causing corrosion and scaling thereof is eliminated. Additionally the heat exchanger includes straightening vanes for preventing startup and other temporary fluctuations in the transitional zone of the boiler from causing brine carryover into the turbine. Also a screen is provided in the heat exchanger to coalesce the working fluid and to assist in defining the location of the transitional zone where the geothermal brine and the isobutane are initially mixed.

  15. Direct contact, binary fluid geothermal boiler

    DOEpatents

    Rapier, Pascal M.

    1982-01-01

    Energy is extracted from geothermal brines by direct contact with a working fluid such as isobutane which is immiscible with the brine in a geothermal boiler. The geothermal boiler provides a distributor arrangement which efficiently contacts geothermal brine with the isobutane in order to prevent the entrainment of geothermal brine in the isobutane vapor which is directed to a turbine. Accordingly the problem of brine carry-over through the turbine causes corrosion and scaling thereof is eliminated. Additionally the heat exchanger includes straightening vanes for preventing startup and other temporary fluctuations in the transitional zone of the boiler from causing brine carryover into the turbine. Also a screen is provided in the heat exchanger to coalesce the working fluid and to assist in defining the location of the transitional zone where the geothermal brine and the isobutane are initially mixed.

  16. Trigonal curves and algebro-geometric solutions to soliton hierarchies II.

    PubMed

    Ma, Wen-Xiu

    2017-07-01

    This is a continuation of a study on Riemann theta function representations of algebro-geometric solutions to soliton hierarchies. In this part, we straighten out all flows in soliton hierarchies under the Abel-Jacobi coordinates associated with Lax pairs, upon determining the Riemann theta function representations of the Baker-Akhiezer functions, and generate algebro-geometric solutions to soliton hierarchies in terms of the Riemann theta functions, through observing asymptotic behaviours of the Baker-Akhiezer functions. We emphasize that we analyse the four-component AKNS soliton hierarchy in such a way that it leads to a general theory of trigonal curves applicable to construction of algebro-geometric solutions of an arbitrary soliton hierarchy.

  17. Evaluation of microfilaricidal effects in the cornea from topically applied drugs in ocular onchocerciasis: Trials with levamisole and mebendazole.

    PubMed Central

    Jones, B R; Anderson, J; Fuglsang, H

    1978-01-01

    Increasing concentrations of levamisole and of mebendazole were applied to 1 eye in groups of 4 patients with ocular onchocerciasis in northern Cameroon. No effect resulted from up to 3.0% mebendazole suspensions, but 3.0% levamisole solutions rapidly caused entry of microfilariae, straightening out and subsequent opacification of previously curled-up living microfilariae, the rapid formation of typical limbal globular infiltrates, and the subsequent formation of fluffy opacities around the microfilariae. These changes are typical of all other drugs so far studied that have a microfilaricidal action on O. volvulus--diethlycarbamizine citrate (DEC), suramin, and metrifonate. The efficacy of 3.0% levamisole approximated to that of 0.03% DEC. This is in keeping with published observations on the filaricidal activity of these 2 compounds. It is suggested that this system of drug testing should be considered for systematic use in the search for more effective and safer drugs for onchocerciasis. Images PMID:678495

  18. Evaluation of microfilaricidal effects in the cornea from topically applied drugs in ocular onchocerciasis: Trials with levamisole and mebendazole.

    PubMed

    Jones, B R; Anderson, J; Fuglsang, H

    1978-07-01

    Increasing concentrations of levamisole and of mebendazole were applied to 1 eye in groups of 4 patients with ocular onchocerciasis in northern Cameroon. No effect resulted from up to 3.0% mebendazole suspensions, but 3.0% levamisole solutions rapidly caused entry of microfilariae, straightening out and subsequent opacification of previously curled-up living microfilariae, the rapid formation of typical limbal globular infiltrates, and the subsequent formation of fluffy opacities around the microfilariae. These changes are typical of all other drugs so far studied that have a microfilaricidal action on O. volvulus--diethlycarbamizine citrate (DEC), suramin, and metrifonate. The efficacy of 3.0% levamisole approximated to that of 0.03% DEC. This is in keeping with published observations on the filaricidal activity of these 2 compounds. It is suggested that this system of drug testing should be considered for systematic use in the search for more effective and safer drugs for onchocerciasis.

  19. Bending of multiwalled carbon nanotubes over gold lines

    NASA Astrophysics Data System (ADS)

    Walkeajärvi, T.; Lievonen, J.; Ahlskog, M.; Åström, J.; Koshio, A.; Yudasaka, M.; Iijima, S.

    2005-11-01

    We have investigated an experimentally moderate bending of multiwalled carbon nanotubes (MWNTs) in the perpendicular direction from flat substrates. The tubes were in the diameter range of 3-13nm and deposited over lithographically fabricated gold lines whose height determined the total bending. In our model for the bending profile we take into account the van der Waals attraction between the substrate and the MWNT and the opposing elastic bending force. With reasonable parameters for the competing forces we obtain an agreement between the model and the experimental data for the critical distance between two adjacent lines when the van der Waals attraction can no longer prevent elastic forces from straightening the tube to a suspended position between the lines. However, for the smallest nanotubes a simple classical model is clearly insufficient.

  20. POLICY EVALUATION FOR THE EFFECTIVE UTILIZATION MEASURES OF EXTENSIVE USED SPACES IN THE CENTRAL AREA OF KUMAMOTO CITY

    NASA Astrophysics Data System (ADS)

    Mizokami, Shoshi; Egawa, Taichi

    Recently, The Open-air Parkin g increases in city center. Therefore, the decline of th e central area is caused as a results and the number of those who visit th e town has decreased. Purposes of research are as follows. It clarifies that landowners and leaseholders that have the Open-air Parking in the central area think land use. It examines that support plan that the administration should do to straighten out that problem. Various support plans are examined from the cost benefit analysis, revenue, and value of support plan. The composition is as follows. In Chapte r 2, it clarifies that landowners and leaseholders that have the Open-air Parking in the central area think land use from "Land use intention investigation". In Chapter 3, the effective profit use usage selection model is presumed. In Chapter 4, the simulation analysis that measures the effect and the value of the support plan is done.

  1. Reconstruction of finger and elbow function after complete avulsion of the brachial plexus.

    PubMed

    Doi, K; Sakai, K; Kuwata, N; Ihara, K; Kawai, S

    1991-09-01

    Simultaneous reconstruction of elbow and finger function with free muscle and nerve transfers after complete avulsion of the brachial plexus (nerve roots C5 to T1) and its long-term results are presented. The basic procedure combined free or vascular pedicle latissimus dorsi muscle transfer with reinnervation by the spinal accessory nerve to obtain elbow and finger flexion, intercostal nerve transfer of the radial nerve to activate elbow and wrist extensors, and suture of the supraclavicular nerve or intercostal sensory rami to the median nerve to restore hand sensibility. Six patients had some or all of these procedures. Postoperative follow-up ranged from 2 to 5 years. Elbow function was restored completely, and some finger flexion was achieved in all cases, although a dynamic splint was necessary to straighten the digits. Patients have continued to improve in grasp power and finger control. This procedure appears to be promising for the restoration of basic hand function in severely handicapped patients.

  2. Use of botulinum toxin in the treatment of ankle plantar flexor spasticity in children with cerebral palsy.

    PubMed

    Mirska, Anna; Cybula, Katarzyna; Okurowska-Zawada, Bożena; Kułak, Wojciech; Dmitruk, Elżbieta; Okulczyk, Kamila; Kalinowska, Anna K

    2014-11-01

    The aim of this study was to assess the effects of botulinum on spasticity of gastrocnemius and soleus muscles. Forty-one children with spastic cerebral palsy were assessed (muscle tone, range of motion of ankle joint extension with straightened and bent knee, and gait pattern using the Physician Rating Scale) before administration and 2, 6, and 13 weeks after. Changes on Physician Rating Scale and dorsiflexion with extended knee were significant after 2, 6, and 13 weeks. Differences in the remaining parameters were significant after the first two check-ups. Over 90% of the changes were positive. This research confirms the effectiveness of botulinum in reducing spasticity, increasing the range of motion, and improving the gait pattern.

  3. The role of nodal and internodal responses in gravitropism and autotropism in Galium aparine L

    NASA Technical Reports Server (NTRS)

    Heathcote, D. G.; Brown, A. H. (Principal Investigator)

    1987-01-01

    This time course and location of gravitropically induced curvatures in stems of goosegrass (Gallium aparine L.), a member of the Rubiaceae, have been investigated. In the early stages of the response (0-5 h), curvature develops throughout the growing region, and is followed by an autotropic straightening which affects the internodes only, leading to the production of essentially straight internodes some 15 h after the onset of gravistimulation. Curvatures developing in the nodal regions, however, continue to increase over this period, and are not subject to reversal by autotropism. The nodal curvatures are not entirely dependent on the presence of any other part of the plant, since marked curvatures can be induced in isolated nodal segments. This pattern of response leads ultimately to correction of the growth direction of the plant by means of curvature responses confined exclusively to the nodes, despite the initial participation of both nodes and internodes in the gravitropic reaction.

  4. Rotating fiber array molecular driver and molecular momentum transfer device constructed therewith

    DOEpatents

    Milleron, Norman

    1983-01-01

    A rotating fiber array molecular driver is disclosed which includes a magnetically suspended and rotated central hub to which is attached a plurality of elongated fibers extending radially therefrom. The hub is rotated so as to straighten and axially extend the fibers and to provide the fibers with a tip speed which exceeds the average molecular velocity of fluid molecules entering between the fibers. Molecules colliding with the sides of the rotating fibers are accelerated to the tip speed of the fiber and given a momentum having a directional orientation within a relatively narrow distribution angle at a point radially outward of the hub, which is centered and peaks at the normal to the fiber sides in the direction of fiber rotation. The rotating fiber array may be used with other like fiber arrays or with other stationary structures to form molecular momentum transfer devices such as vacuum pumps, molecular separators, molecular coaters, or molecular reactors.

  5. Endodontic Management of the Three-Rooted Mandibular First Permanent Molar: a Case Report.

    PubMed

    Štamfelj, Iztok

    2014-09-01

    The distal root of the mandibular first permanent molar (MFPM) contains one or two canals. More rarely, the second/third distal canal is found in a separate root in a distolingual (DL) position - a radix entomolaris (RE). In Caucasians, this occurs in less than 4% of cases, but it is equally important to be aware of this possibility. Careful examination of the preoperative periapical radiographs (orthoradial and mesially angled) and inspection of the pulp chamber floor during endodontic management may indicate that this radicular variant is present. RE's lingual inclination and buccolingual curvature must be taken into account during cleaning and shaping of the canal within this root to avoid procedural errors, such as straightening and ledging of the root canal, perforation or instrument fracture. The aim of the present paper was to discuss a case report of a young patient, referred to an endodontic office after a ledge was created by inappropriate instrumentation of a buccolingually curved RE canal.

  6. [Current therapeutic options for Peyronie's disease].

    PubMed

    Hauptmann, A; Diemer, T; Weidner, W

    2013-10-01

    Peyronie's disease is a heterogeneous disorder with typical symptoms of plaque formation, penile pain, deviation, penile shortening and erectile dysfunction. The etiology is unknown. Repetitive microtraumatic lesions with the formation of inelastic scar tissue at the level of the tunica albuginea are discussed as a trigger mechanism for a questionable genetic disposition. A non-surgical therapy based on a clear pathophysiology does not exist although several conservative treatment regimes are practiced. In the stable stage of the disease surgical therapy of penile angulation is the most frequent operation. Depending on the deviation angle, penile length and erectile dysfunction, different types of straightening surgery can be offered. This article provides an overview of conservative management and commonly used surgical techniques.

  7. Structural Dynamics of an Actin Spring

    PubMed Central

    Mahadevan, L.; Riera, C.S.; Shin, Jennifer H.

    2011-01-01

    Actin-based motility in cells is usually associated with either polymerization/depolymerization in the presence of cross-linkers or contractility in the presence of myosin motors. Here, we focus on a third distinct mechanism involving actin in motility, seen in the dynamics of an active actin spring that powers the acrosomal reaction of the horseshoe crab (Limulus polyphemus) sperm. During this process, a 60-μm bent and twisted bundle of cross-linked actin uncoils and becomes straight in a few seconds in the presence of Ca2+. This straightening, which occurs at a constant velocity, allows the acrosome to forcefully penetrate the egg. Synthesizing ultrastructural information with the kinetics, energetics, and imaging of calcium binding allows us to construct a dynamical theory for this mechanochemical engine consistent with our experimental observations. It also illuminates the general mechanism by which energy may be stored in conformational changes and released cooperatively in ordered macromolecular assemblies. PMID:21320427

  8. Dental Arch Wire

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Straightening teeth is an arduous process requiring months, often years, of applying corrective pressure by means of arch wires-better known as brace-which may have to be changed several times in the course of treatment. A new method has been developed by Dr. George Andreasen, orthodontist and dental scientist at the University of Iowa. The key is a new type of arch wire material, called Nitinol, with exceptional elasticity which helps reduce the required number of brace changes. An alloy of nickel and titanium, Nitinol was originally developed for aerospace applications by the Naval Ordnance Laboratory, now the Naval Surface Weapons Laboratory, White Oaks, Maryland. NASA subsequently conducted additional research on the properties of Nitinol and on procedures for processing the metal.

  9. Self-organization of cooperative grain boundary sliding in aluminium tricrystals

    SciTech Connect

    Astanin, V.V.; Sisanbaev, A.V.; Pshenichnyuk, A.I.; Kaibyshev, O.A.

    1997-01-01

    Grain boundary sliding (GBS) being an important mechanism of high temperature deformation of polycrystals acquires a leading role in microcrystalline materials providing a superplasticity effect in them. Self-organization of change (increase) in angles of triple junctions providing CGBS realization was experimentally studied in a number of works. In particular, it was established that long range chains of grain boundaries are formed in structure of different materials. That is due to superplastic deformation. These chains are arranged almost in a straight line. Many well-known models on accommodation of GBS during superplastic deformation suggest the straightening of triple junctions. However, driving force and mechanisms of such transformation remain unclear in many cases. The aim of the present work is to design a transmission of GBS via a triple junction, to show physical origin of the triple junction transformation and to suggest a mechanism of the process. Well attested tricrystals are the best two dimensional model objects for such investigations.

  10. Riparian vegetation recovery patterns following stream channelization: a geomorphic perspective

    USGS Publications Warehouse

    Hupp, C.R.

    1992-01-01

    Hundreds of kilometres of West Tennessee streams have been channelized since the turn of the century. After a stream is straightened, dredged, or cleared, basin-wide ecologic, hydrologic, and geomorphic processes bring about an integrated, characteristic recovery sequence. The rapid pace of channel responses to channelization provides an opportunity to document and interpret vegetation recovery patterns relative to otherwise long-term, concomitant evolution of river geomorphology. The linkage of channel bed aggradation, woody vegetation establishment, and bank accretion all lead to recovery of the channel. Pioneer species are hardy and fast growing, and can tolerate moderate amounts of slope instability and sediment deposition; these species include river birch (Betula nigra), black willow (Salix nigra), boxelder (Acer negundo), and silver maple (Acer saccharinum). High stem densities and root-mass development appear to enhance bank stability. Tree-ring analyses suggest that on average 65 yr may be required for recovery after channelization. -from Author

  11. Peyronie's Reconstruction for Maximum Length and Girth Gain: Geometrical Principles

    PubMed Central

    Egydio, Paulo H.; Sansalone, Salvatore

    2008-01-01

    Peyronie's disease has been associated with penile shortening and some degree of erectile dysfunction. Surgical reconstruction should be based on giving a functional penis, that is, rectifying the penis with rigidity enough to make the sexual intercourse. The procedure should be discussed preoperatively in terms of length and girth reconstruction in order to improve patient satisfaction. The tunical reconstruction for maximum penile length and girth restoration should be based on the maximum length of the dissected neurovascular bundle possible and the application of geometrical principles to define the precise site and size of tunical incision and grafting procedure. As penile rectification and rigidity are required to achieve complete functional restoration of the penis and 20 to 54% of patients experience associated erectile dysfunction, penile straightening alone may not be enough to provide complete functional restoration. Therefore, phosphodiesterase inhibitors, self-injection, or penile prosthesis may need to be added in some cases. PMID:19081785

  12. Thoracoabdominal aortic aneurysm in an infant treated by thromboexclusion with thoracoabdominal aortic bypass. A case report.

    PubMed

    Hashimoto, R; Hada, M; Kamiya, K; Tada, Y; Ueno, A; Yanai, J; Komai, T

    1996-12-01

    A case of a huge thoracoabdominal aortic aneurysm in an eighteen-month-old boy is reported. Surgical treatment was successfully performed by thromboexclusion of the aneurysm with thoracoabdominal aortic bypass using a low-porosity woven Dacron graft 10 mm in diameter and of sufficient surplus length. During the early postoperative period, he developed moderate hydronephrosis, owing to compression of the left ureter by the graft, but no further deterioration was seen. Follow-up angiographies performed four and six years after surgery revealed straightening of the graft and slight stretching of the aorta at the distal anastomosis, but no stenosis was found. Now, seven and a half years after surgery, he has no pressure gradient between upper and lower extremities.

  13. Pseudo-phase Diagram of Cholesterol-Rich Filamentous, Helical Ribbon, and Crystal Microstructures

    NASA Astrophysics Data System (ADS)

    Miroshnikova, Y. A.; Elsenbeck, M.; Ou, Guanqing; Zastavker, Y. V.; Kashuri, K.; Iannacchione, G. S.

    2009-03-01

    Optical and calorimetric techniques are employed to study temperature and concentration dependence of three self-assembled microstructure types formed in Chemically Defined Lipid Concentrate (CDLC): filaments, helical ribbons, and crystals. CDLC consists of cholesterol, bilayer-forming amphiphiles, and micelle-forming amphiphiles in water, and is considered to be a model system for cholesterol crystallization in gallbladder bile. Phase contrast and DIC microscopy indicate the presence of all three microstructure types in all samples studied. Optically observed structural evolution indicates that filaments first bend to form helical ribbons followed by clustering and ``straightening'' of these structures into short and increasingly thickening filaments that dissolve with increasing temperature. Complementary calorimetric studies (differential-scanning and modulation) reveal thermal signatures that correspond to this observed structural evolution, which occurs throughout a large region of metastable chemical coexistence. These results suggest that a pseudo-phase diagram for the microstructures formed in CDLC may be developed to explain the observed behavior of the system.

  14. Polarization-resolved SHG microscopy of rat-tail tendon with controlled mechanical strain

    NASA Astrophysics Data System (ADS)

    Gusachenko, I.; Goulam Houssen, Y.; Tran, V.; Allain, J.-M.; Schanne-Klein, M.-C.

    2013-06-01

    We combined polarization-resolved SHG microscopy with mechanical assays in rat-tail-tendon and measured collagen remodeling upon controlled stretching. This approach aimed to analyze the relationship between macroscopic response and sub-micrometer scale organization of collagen fibrils. We observed a straightening of the crimps followed by a sliding of the fibrils with increasing stretching of the tendon fascicles. Polarization resolution of the SHG images provided complementary information about the orientation dispersion of collagen fibrils within the focal volume and enabled monitoring of collagen remodeling at the sub-micrometer scale. Our approach can be readily generalized to other tissues and should bring new valuable information about biomechanics of microstructured tissues.

  15. A standard cytogenetic photomap for the mosquito Anopheles stephensi (Diptera: Culicidae): application for physical mapping.

    PubMed

    Sharakhova, Maria V; Xia, Ai; McAlister, Sarah I; Sharakhov, Igor V

    2006-09-01

    To facilitate physical genome mapping, we have developed a new cytogenetic photomap for Anopheles stephensi (Liston) (Diptera: Culicidae), an important malaria vector in Asia. The high-resolution images of the ovarian polytene chromosomes have been straightened and divided by numbered divisions and lettered subdivisions. The exact chromosomal locations of eight DNA probes have been determined by fluorescent in situ hybridization. Using the DNA sequences, we have established correspondence between chromosomal arms among An. stephensi, Anopheles gambiae (Patton), and Anopheles funestus (Giles). The results support previous cytogenetic observations of arm translocations taking place during diversification of the species. To make the cytogenetic map useful for population genetics studies, we have indicated the chromosomal positions for the breakpoints of 19 polymorphic inversions.

  16. Histology of the mucosa of the oesophagogastric junction and the stomach in adult Rana perezi.

    PubMed Central

    Gallego-Huidobro, J; Pastor, L M

    1996-01-01

    The histological structure of the frog digestive mucosa changes at the oesophagogastric junction. The pseudostratified ciliated mucosal epithelium of oesophageal type changes to a simple mucus-secreting epithelium of gastric type. The glands straighten and the muscularis mucosae develops as a complete layer. The muscularis increases in thickness. Unlike the mammalian stomach, in the frog the surface of the plicae forms convoluted ridges that delimit furrow-shaped pits. Two types of gastric glands are distinguished, fundal and pyloric. The former consist of mucous, oxynticopeptic and endocrine cells. The pyloric glandular cells are mainly of mucus-secreting type with scattered endocrine cells. Scattered endocrine cells of P, D, G, A, EC, and EC-L-like types are found in the glands along the stomach. It is concluded that the mucosal structure of the anuran oesophagogastric junction and stomach is less complicated than that of mammals, including man. Images Fig. 1 Fig. 2 PMID:8621343

  17. Nanoscale manipulation of Ge nanowires by ion hammering

    SciTech Connect

    Picraux, Samuel T; Romano, Lucia; Rudawski, Nicholas G; Holzworth, Monta R; Jones, Kevin S; Choi, S G

    2009-01-01

    Nanowires generated considerable interest as nanoscale interconnects and as active components of both electronic and electromechanical devices. However, in many cases, manipulation and modification of nanowires are required to realize their full potential. It is essential, for instance, to control the orientation and positioning of nanowires in some specific applications. This work demonstrates a simple method to reversibly control the shape and the orientation of Ge nanowires by using ion beams. Initially, crystalline nanowires were partially amorphized by 30 keY Ga+-implantation. After amorphization, viscous flow and plastic deformation occurred due to the ion hammering effect, causing the nanowires to bend toward the beam direction. The bending was reversed multiple times by ion-implanting the opposite side of the nanowires, resulting in straightening of the nanowires and subsequent bending in the opposite direction. This ion hammering effect demonstrates the detailed manipulation of nanoscale structures is possible through the use of ion irradiation.

  18. Penile deviation--our therapeutic concept.

    PubMed

    Lenk, S; Schönberger, B

    1994-01-01

    Penile deviations can be congenital or acquired, e.g. Peyronie's disease, and--depending on the degree of curvature--can impede cohabitation or make it completely impossible. 53 patients (17 congenital, 36 acquired) with penile curvature were examined as to anamnesis, clinical state, autophotography or artificial erection with the help of vasoactive drugs or a vacuum device. A pharmacocavernosography was performed in patients with erectile problems. In cases of congenital deviation, surgical correction was carried out according to the Nesbit procedure, and in 2 patients with hypoplastic urethra after penile straightening a urethroplasty was performed. Twenty-eight patients with Peyronie's disease were treated with superoxide dismutase. Seven of them had to be operated on, and in 8 patients with severe deviation surgical therapy was primary. In conclusion, the management of penile deviation should be differentiated depending on the cause and degree of deviation as well as discomfort and erectile potency.

  19. Two Long Filaments

    NASA Image and Video Library

    2016-09-08

    The two most noteworthy features on the sun this week were a pair of elongated filaments (Sept. 8, 2016). The central one was twisted into the shape of an elaborate arch at the center of the sun (yellow arrows). If this were straightened out, it would extend just about across the entire sun, almost a million miles (1.6 million Km). The other, smaller filament, (white arrows) if made straight, might reach about half that distance. Still, pretty impressive. Filaments are elongated strands of plasma suspended above the sun by magnetic forces. They are notoriously unstable and often break apart within a few days. The image was made by combining three images in different wavelengths of extreme ultraviolet light http://photojournal.jpl.nasa.gov/catalog/PIA16996

  20. Endoscopes and robots for tight surgical spaces: use of precurved elastic elements to enhance curvature

    NASA Astrophysics Data System (ADS)

    Remirez, Andria A.; Webster, Robert J.

    2016-03-01

    Many applications in medicine require flexible surgical manipulators and endoscopes capable of reaching tight curvatures. The maximum curvature these devices can achieve is often restricted either by a strain limit, or by a maximum actuation force that the device's components can tolerate without risking mechanical failure. In this paper we propose the use of precurvature to "bias" the workspace of the device in one direction. Combined with axial shaft rotation, biasing increases the size of the device's workspace, enabling it to reach tighter curvatures than a comparable device without biasing can achieve, while still being able to fully straighten. To illustrate this effect, we describe several example prototype devices which use flexible nitinol strips that can be pushed and pulled to generate bending. We provide a statics model that relates the manipulator curvature to actuation force, and validate it experimentally.

  1. Mechanical characteristics of novel polyester/NiTi wires braided composite stent for the medical application

    NASA Astrophysics Data System (ADS)

    Zou, Qiuhua; Xue, Wen; Lin, Jing; Fu, Yijun; Guan, Guoping; Wang, Fujun; Wang, Lu

    Stents have been widely used in percutaneous surgery to treat stenosis diseases. The braided NiTi stent, as a promising prototype, still has limitations of low radial force and loose structure. In the present study, a newly integrated composite stent was designed and braided with NiTi wires and polyester multifilament yarns by textile technology. The mechanical properties of four composite stents and the control bare NiTi stent were evaluated by in vitro compression, bending and anti-torsion tests. The results showed that integrated polyester/NiTi composite stents were superior in radial support. The stents could keep patency even when highly curved and had lower stent straightening force. Composite stents with certain structure stayed stable under twisting. The configuration of NiTi wires in composite stents could significantly impact stent deformation under twisting.

  2. On the tear resistance of skin

    NASA Astrophysics Data System (ADS)

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-03-01

    Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.

  3. World-to-chip interconnects for efficient loading of genomic DNA into microfluidic channels

    NASA Astrophysics Data System (ADS)

    Humphreys, Tim; Andersson, Johan; Södervall, Ulf; Melvin, Tracy

    2009-10-01

    A novel sloped interconnect for the efficient delivery of long genomic DNA fragments into a microfluidic channel is designed, fabricated and tested. Out-of-plane slopes are fabricated in silicon wafers using the deep reactive-ion etch lag phenomenon and a combination of anisotropic and isotropic etching. The final structure is capped with anodically bonded glass. Based upon a series of etch-lag calibration studies, the interconnect was designed using finite element analysis to provide a channel with flow acceleration properties appropriate to straighten DNA molecules. The efficiency of transit of the 48.5 kb DNA fragments (~16.5 µm long when fully extended) through the microfluidic device, established using quantitative real-time polymerase chain reaction, is 95 ± 7.3%.

  4. S-192 analysis: Conventional and special data processing techniques. [Michigan

    NASA Technical Reports Server (NTRS)

    Nalepka, R. F. (Principal Investigator); Morganstern, J.; Cicone, R.; Sarno, J.; Lambeck, P.; Malila, W.

    1975-01-01

    The author has identified the following significant results. Multispectral scanner data gathered over test sites in southeast Michigan were analyzed. This analysis showed the data to be somewhat deficient especially in terms of the limited signal range in most SDOs and also in regard to SDO-SDO misregistration. Further analysis showed that the scan line straightening algorithm increased the misregistration of the data. Data were processed using the conic format. The effects of such misregistration on classification accuracy was analyzed via simulation and found to be significant. Results of employing conventional as well as special, unresolved object, processing techniques were disappointing due, at least in part, to the limited signal range and noise content of the data. Application of a second class of special processing techniques, signature extension techniques, yielded better results. Two of the more basic signature extension techniques seemed to be useful in spite of the difficulties.

  5. On load paths and load bearing topology from finite element analysis

    NASA Astrophysics Data System (ADS)

    Kelly, D.; Reidsema, C.; Lee, M.

    2010-06-01

    Load paths can be mapped from vector plots of 'pointing stress vectors'. They define a path along which a component of load remains constant as it traverses the solution domain. In this paper the theory for the paths is first defined. Properties of the plots that enable a designer to interpret the structural behavior from the contours are then identified. Because stress is a second order tensor defined on an orthogonal set of axes, the vector plots define separate paths for load transfer in each direction of the set of axes. An algorithm is therefore presented that combines the vectors to define a topology to carry the loads. The algorithm is shown to straighten the paths reducing bending moments and removing stress concentration. Application to a bolted joint, a racing car body and a yacht hull demonstrate the usefulness of the plots.

  6. Fabrication of highly conductive carbon nanotube fibers for electrical application

    NASA Astrophysics Data System (ADS)

    Guo, Fengmei; Li, Can; Wei, Jinquan; Xu, Ruiqiao; Zhang, Zelin; Cui, Xian; Wang, Kunlin; Wu, Dehai

    2015-09-01

    Carbon nanotubes (CNTs) have great potential for use as electrical wires because of their outstanding electrical and mechanical properties. Here, we fabricate lightweight CNT fibers with electrical conductivity as high as that of stainless steel from macroscopic CNT films by drawing them through diamond wire-drawing dies. The entangled CNT bundles are straightened by suffering tension, which improves the alignment of the fibers. The loose fibers are squeezed by the diamond wire-drawing dies, which reduces the intertube space and contact resistance. The CNT fibers prepared by drawing have an electrical conductivity as high as 1.6 × 106 s m-1. The fibers are very stable when kept in the air and under cyclic tensile test. A prototype of CNT motor is demonstrated by replacing the copper wires with the CNT fibers.

  7. Method and apparatus for injection of tubing into wells

    SciTech Connect

    Gipson, T.C.

    1987-06-16

    A tubing injector is described comprising: a frame; a subframe slidably mounted on the frame; tubing storage means mounted on the subframe and having coil tubing stored thereon; an injector reel rotatably mounted on the frame; means for rotating the injector reel; means mounted around a portion of the circumference of the injector reel for exerting pressure against the coiled tubing when the coil tubing is directed between the pressure exerting means and the circumference of the injector reel to provide positive engagement of the tubing by the injector reel when the injector reel is being rotated to pull the tubing off of the tubing storage means or return the tubing to the tubing storage means; means for straightening the tubing; and means for slidably reciprocating the subframe across the frame during the return of the tubing to the tubing storage means.

  8. Equations determine coiled tubing collapse pressure

    SciTech Connect

    Avakov, V.; Taliaferro, W.

    1995-07-24

    A set of equations has been developed for calculating pipe collapse pressure for oval tubing such as coiled tubing. When coiled tubing is placed onto a reel, the tubing is forced into an oval shape and never again returns to perfect roundness because the coiling process exceeds the plasticity limits of the tubing. Straightening the tubing for the trip into the well does not restore roundness. The consequence of this physical property is that all coiled tubing collapse pressure calculations should be made considering oval tubing, not round tubing. Tubing collapse can occur when formation pressure against the coiled tubing exceeds the collapse resistance inherent in the coiled tubing. As coiled tubing becomes more oval in shape, it becomes more oval in shape, it becomes more susceptible to collapse from outside pressure.

  9. Characterizing a large shear-zone with seismic and magnetotelluric methods: The case of the Dead Sea Transform

    USGS Publications Warehouse

    Maercklin, N.; Bedrosian, P.A.; Haberland, C.; Ritter, O.; Ryberg, T.; Weber, M.; Weckmann, U.

    2005-01-01

    Seismic tomography, imaging of seismic scatterers, and magnetotelluric soundings reveal a sharp lithologic contrast along a ???10 km long segment of the Arava Fault (AF), a prominent fault of the southern Dead Sea Transform (DST) in the Middle East. Low seismic velocities and resistivities occur on its western side and higher values east of it, and the boundary between the two units coincides partly with a seismic scattering image. At 1-4 km depth the boundary is offset to the east of the AF surface trace, suggesting that at least two fault strands exist, and that slip occurred on multiple strands throughout the margin's history. A westward fault jump, possibly associated with straightening of a fault bend, explains both our observations and the narrow fault zone observed by others. Copyright 2005 by the American Geophysical Union.

  10. Laser reshaping of nasal septum cartilage: clinical results for 40 patients

    NASA Astrophysics Data System (ADS)

    Sobol, Emil N.; Sviridov, Alexander P.; Bagratashvili, Victor N.; Omelchenko, Alexander I.; Ovchinnikov, Yuriy M.; Shekhter, Anatoliy B.; Svistushkin, Valeriy M.; Shinaev, Alexander N.

    2000-05-01

    Clinical results on sparing laser reshaping of nasal septum cartilage are reported for the first time. Forty patients have been treated with holmium laser to correct a deformed cartilage. The laser reshaping is a bloodless, painless procedure which takes few minutes to straighten nasal septum. The stability of the new shape and possible side effects have been examined during twelve months. The headache and other negative symptoms have disappeared, as a result of laser treatment for the most of patients. Rhinoscopic examination show an excellent long-term reshaping effects for nasal septum of 23 patients, and, also, good results for other 12 patients. For 5 patients only a little effect takes place. Our rhinomanometric examinations demonstrate a pronounced improvement of the breathing for 35 patients. No visible undesirable side effects were observed for all patients underwent to laser reshaping procedure.

  11. Translational control of a graphically simulated robot arm by kinematic rate equations that overcome elbow joint singularity

    NASA Technical Reports Server (NTRS)

    Barker, L. K.; Houck, J. A.; Carzoo, S. W.

    1984-01-01

    An operator commands a robot hand to move in a certain direction relative to its own axis system by specifying a velocity in that direction. This velocity command is then resolved into individual joint rotational velocities in the robot arm to effect the motion. However, the usual resolved-rate equations become singular when the robot arm is straightened. To overcome this elbow joint singularity, equations were developed which allow continued translational control of the robot hand even though the robot arm is (or is nearly) fully extended. A feature of the equations near full arm extension is that an operator simply extends and retracts the robot arm to reverse the direction of the elbow bend (difficult maneuver for the usual resolved-rate equations). Results show successful movement of a graphically simulated robot arm.

  12. High quality AlN epilayers grown on nitrided sapphire by metal organic chemical vapor deposition.

    PubMed

    Wang, Jiaming; Xu, Fujun; He, Chenguang; Zhang, Lisheng; Lu, Lin; Wang, Xinqiang; Qin, Zhixin; Shen, Bo

    2017-02-21

    Influence of sapphire pretreatment conditions on crystalline quality of AlN epilayers has been investigated by metal organic chemical vapor deposition (MOCVD). Compared to alumination treatment, it is found that appropriate sapphire nitridation significantly straightens the surface atomic terraces and decreases the X-ray diffraction (0002) full width at half maximum (FWHM) to a minimum of 55 arcsec, indicating a great improvement of the tilting feature of the grain structures in the AlN epilayer. More importantly, there is no inversion domains (IDs) found in the AlN epilayers, which clarifies that optimal sapphire nitridation is promising in the growth of high quality AlN. It is deduced that the different interfacial atomic structures caused by various pretreatment conditions influence the orientation of the AlN nucleation layer grains, which eventually determines the tilting features of the AlN epilayers.

  13. Examining the feasibility of implementing specific nursing interventions to promote sleep in hospitalized elderly patients.

    PubMed

    Lareau, Rita; Benson, Linda; Watcharotone, Kuanwong; Manguba, Grace

    2008-01-01

    Sleep deprivation and subsequent effects on health restoration have been documented in the literature. The purpose of this experimental pilot study was to examine the feasibility of implementing specific nursing interventions to promote sleep in hospitalized older adults. The experimental group received a sleep protocol intervention while the control group received usual nighttime care. While no differences were noted in sleep quality and duration between groups, the experimental group experienced better sleep quality (P = .001), ability to remain asleep (P = .018) and used fewer sleep medications than the control group (P = .044). In addition, those taking sleep medications experienced more awakenings and fewer sleep hours. Experimental group patients identified preferences such as personal hygiene, awareness of normal bedtime, receiving a back rub, straightening bed linens, and receiving a bedtime snack. This pilot provides initial support for the feasibility and utility of implementing a sleep protocol in an acute care setting.

  14. High quality AlN epilayers grown on nitrided sapphire by metal organic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Wang, Jiaming; Xu, Fujun; He, Chenguang; Zhang, Lisheng; Lu, Lin; Wang, Xinqiang; Qin, Zhixin; Shen, Bo

    2017-02-01

    Influence of sapphire pretreatment conditions on crystalline quality of AlN epilayers has been investigated by metal organic chemical vapor deposition (MOCVD). Compared to alumination treatment, it is found that appropriate sapphire nitridation significantly straightens the surface atomic terraces and decreases the X-ray diffraction (0002) full width at half maximum (FWHM) to a minimum of 55 arcsec, indicating a great improvement of the tilting feature of the grain structures in the AlN epilayer. More importantly, there is no inversion domains (IDs) found in the AlN epilayers, which clarifies that optimal sapphire nitridation is promising in the growth of high quality AlN. It is deduced that the different interfacial atomic structures caused by various pretreatment conditions influence the orientation of the AlN nucleation layer grains, which eventually determines the tilting features of the AlN epilayers.

  15. High quality AlN epilayers grown on nitrided sapphire by metal organic chemical vapor deposition

    PubMed Central

    Wang, Jiaming; Xu, Fujun; He, Chenguang; Zhang, Lisheng; Lu, Lin; Wang, Xinqiang; Qin, Zhixin; Shen, Bo

    2017-01-01

    Influence of sapphire pretreatment conditions on crystalline quality of AlN epilayers has been investigated by metal organic chemical vapor deposition (MOCVD). Compared to alumination treatment, it is found that appropriate sapphire nitridation significantly straightens the surface atomic terraces and decreases the X-ray diffraction (0002) full width at half maximum (FWHM) to a minimum of 55 arcsec, indicating a great improvement of the tilting feature of the grain structures in the AlN epilayer. More importantly, there is no inversion domains (IDs) found in the AlN epilayers, which clarifies that optimal sapphire nitridation is promising in the growth of high quality AlN. It is deduced that the different interfacial atomic structures caused by various pretreatment conditions influence the orientation of the AlN nucleation layer grains, which eventually determines the tilting features of the AlN epilayers. PMID:28220829

  16. Two-state model for nematic liquid crystals made of bent-core molecules

    NASA Astrophysics Data System (ADS)

    Madhusudana, N. V.

    2017-08-01

    Nematic (N ) liquid crystals made of bent-core molecules exhibit unusual physical properties such as an intermediate phase between the N and isotropic (I ) phases, a very weak N I transition as inferred from magnetic birefringence measurements in a low field, which is apparently incompatible with a large shift in the N I transition temperature (Tn i) measured under a high field. Using our conformational studies on the aromatic cores, we propose that only conformers which are more straightened than those in the ground state (GS) form clusters with a few layers, which persist even in the isotropic phase, as inferred from x-ray and rheological experiments. We present a Landau-de Gennes theory of the medium, including an orientational coupling between the clusters and the GS molecules, which accounts for all the unusual properties. The intermediate phase to isotropic transition is predicted to exhibit critical behavior at a very low magnetic field of <1 kG .

  17. Removal of Axial Twist in RHIC Insertion Quadrupole Magnets

    NASA Astrophysics Data System (ADS)

    Cozzolino, J.; Anerella, M.; Jain, A.; Louie, W.; Muratore, P.

    1997-05-01

    The focusing triplets located on either side of the six interaction points of RHIC each consist of three 13cm aperture quadrupoles with magnetic lengths of 1.44m (Q1), 3.40m (Q2), and 2.10m (Q3). The field quality and alignment of these magnets are most critical to the performance of the accelerator. The maximum allowable axial twist of the cold mass, defined as the standard deviation in the quadrupole roll angle, is 0.5 mrad. This requirement has occasionally exceeded the capabilities of the assembly fixturing and the procedures used to complete the axial welding of the shell halves around the cold mass yoke. A corrective shell welding technique has been successfully employed to remove excessive axial twist of the 13cm quadrupoles. This ``custom straightening" method will be described along with the before and after mechanical inspection data. The magnetic results which confirm the untwisting procedure shall also be discussed.

  18. Using Modelica to investigate the dynamic behaviour of the German national standard for high pressure natural gas flow metering

    NASA Astrophysics Data System (ADS)

    von der Heyde, M.; Schmitz, G.; Mickan, B.

    2016-08-01

    This paper presents a computational model written in Modelica for the high pressure piston prover (HPPP) used as the national primary standard for high pressure natural gas flow metering in Germany. With a piston prover the gas flow rate is determined by measuring the time a piston needs to displace a certain volume of gas in a cylinder. Fluctuating piston velocity during measurement can be a significant source of uncertainty if not considered in an appropriate way. The model was built to investigate measures for the reduction of this uncertainty. Validation shows a good compliance of the piston velocity in the model with measured data for certain volume flow rates. Reduction of the piston weight, variation of the start valve switching time and integration of a flow straightener were found to reduce the piston velocity fluctuations in the model significantly. The fast and cost effective generation of those results shows the strength of the used modelling approach.

  19. On the tear resistance of skin

    PubMed Central

    Yang, Wen; Sherman, Vincent R.; Gludovatz, Bernd; Schaible, Eric; Stewart, Polite; Ritchie, Robert O.; Meyers, Marc A.

    2015-01-01

    Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip. PMID:25812485

  20. Non-undulatory locomotion in the lamprey.

    PubMed

    Archambault, P S; Deliagina, T G; Orlovsky, G N

    2001-07-03

    The lamprey (a lower vertebrate, cyclostome), in addition to ordinary swimming, is also capable of crawling. Here we describe crawling forward in a narrow U-shaped tunnel. A rapid movement along the tunnel was evoked by stimulating the tail. The muscle activity responsible for propulsion was confined to the area around the body bend. Muscles on the inner (concave) side were activated when approaching the turn, and inactivated on the top of the arc. Muscles on the outer (convex) side were co-active with their antagonists, but also active in the area of straightening of the body bend. This pattern of muscle activity propagated along the body. The role of central and reflex mechanisms in the generation of locomotor movements is discussed.

  1. Collagenase injections for treatment of Dupuytren disease.

    PubMed

    Hentz, Vincent R

    2014-02-01

    Palmodigital fasciectomy remains the gold standard. The initial outcome is, in my experience, far more predictable than either NA or enzyme fasciotomy (EF). It is also a more durable treatment. NA and EF can be conceptualized as similar procedures--one uses a needle and the other an enzyme to weaken a cord sufficient to be able to rupture it and thus straighten a contracted joint. Both are less invasive and the hand is quick to recover. Both procedures are equally initially effective. CHH seems to offer greater durability. Today’s patients are often better educated and seek a specific type of treatment, in particular, effective nonoperative treatment. Pharmaceutical companies now market directly and effectively to patients, and this strategy and Internet use have already resulted in an increase in the number of patients searching for practitioners willing to administer and capable of administering collagenase treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Decomposition of the (2 + 1)- dimensional Gardner equation and its quasi-periodic solutions

    NASA Astrophysics Data System (ADS)

    Geng, Xianguo; Cao, Cewen

    2001-11-01

    To decompose the (2 + 1)-dimensional Gardner equation, an isospectral problem and a corresponding hierarchy of (1 + 1)-dimensional soliton equations are proposed. The (2 + 1)-dimensional Gardner equation is separated into the first two non-trivial (1 + 1)-dimensional soliton systems in the hierarchy, and in turn into two new compatible Hamiltonian systems of ordinary differential equations. Using the generating function flow method, the involutivity and the functional independence of the integrals are proved. The Abel-Jacobi coordinates are introduced to straighten out the associated flows. The Riemann-Jacobi inversion problem is discussed, from which quasi-periodic solutions of the (2 + 1)-dimensional Gardner equation are obtained by resorting to the Riemann theta functions.

  3. Scarring alopecia: clinical and pathologic study of 54 African-American women.

    PubMed

    Borovicka, Judy H; Thomas, Lorna; Prince, Carol; Mehregan, Darius R

    2009-08-01

    Cicatricial or scarring alopecia results in the destruction of hair follicles and is a significant cosmetic concern in African-American women. To correlate the clinical examination and histologic findings in African-American women with scarring alopecia with a history of hairstyling practices. We reviewed retrospectively the medical records and scalp biopsy specimens of 54 women with scarring alopecia. Patients were selected from two dermatologic practices in the Detroit Metropolitan area. Alopecia commonly presents in patients who use a variety of traumatic haircare techniques, including chemical and physical straighteners, traction, braiding, hair extensions, hair gluing, and chemical curls. Histologic findings are centered around the follicular infundibulum with a lymphocytic infiltrate and perifollicular fibrosis. Traumatic hairstyling techniques are common in African-American women, and all result in a similar picture of a peri-infundibular lymphocytic infiltrate and fibrosis, leading to alopecia.

  4. Cerebral arteriopathy associated with Arg179His ACTA2 mutation.

    PubMed

    Amans, Matthew R; Stout, Charles; Fox, Christine; Narvid, Jared; Hetts, Steven W; Cooke, Daniel L; Higashida, Randall T; Dowd, Christopher F; McSwain, Hugh; Halbach, Van V

    2014-11-01

    ACTA2 mutations have recently been shown to cause a multisystem smooth muscle dysfunction syndrome that may result in pediatric stroke. We report a case of ACTA2 mutation in a 3-year-old girl presenting with acute ischemic stroke and provide high resolution imaging of the cerebral arteries demonstrating novel findings of multiple tiny aneurysms (particularly in the posterior circulation), as well as the more characteristic imaging phenotype of straightened and narrowed proximal intracranial vessels, dilated cervical vessels and occlusion of the M1 MCA segment without lenticulostriate collateral formation. This newly identified disease should be added to the differential diagnosis of pediatric stroke and cerebral vasculopathy. Neuroradiologists, interventionalists, surgeons and neurologists should become familiar with this rare disease and its clinical sequelae. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. A method of calibrating wind velocity sensors with a modified gas flow calibrator

    NASA Technical Reports Server (NTRS)

    Stump, H. P.

    1978-01-01

    A procedure was described for calibrating air velocity sensors in the exhaust flow of a gas flow calibrator. The average velocity in the test section located at the calibrator exhaust was verified from the mass flow rate accurately measured by the calibrator's precision sonic nozzles. Air at elevated pressures flowed through a series of screens, diameter changes, and flow straighteners, resulting in a smooth flow through the open test section. The modified system generated air velocities of 2 to 90 meters per second with an uncertainty of about two percent for speeds below 15 meters per second and four percent for the higher speeds. Wind tunnel data correlated well with that taken in the flow calibrator.

  6. Molecular Order of Arterial Collagen Using Circular Polarization Second-Harmonic Generation Imaging

    PubMed Central

    Turcotte, Raphaël; Mattson, Jeffrey M.; Wu, Juwell W.; Zhang, Yanhang; Lin, Charles P.

    2016-01-01

    Second-harmonic generation (SHG) originates from the interaction between upconverted fields from individual scatterers. This renders SHG microscopy highly sensitive to molecular distribution. Here, we aim to take advantage of the difference in SHG between aligned and partially aligned molecules to probe the degree of molecular order during biomechanical testing, independently of the absolute orientation of the scattering molecules. Toward this goal, we implemented a circular polarization SHG imaging approach and used it to quantify the intensity change associated with collagen fibers straightening in the arterial wall during mechanical stretching. We were able to observe the delayed alignment of collagen fibers during mechanical loading, thus demonstrating a simple method to characterize molecular distribution using intensity information alone. PMID:26806883

  7. Quantifying hair shape and hair damage induced during reshaping of hair.

    PubMed

    McMullen, Roger L; Zhang, Guojin; Gillece, Timothy

    2015-01-01

    The manipulation of hair shape, either to straighten or curl hair, is carried out on a grand scale in the hair care consumer market. Often, such changes are brought about through chemical or physical treatment, resulting in changes to hair chemistry. In this article, we review existing and present new data on methods to assess the efficacy of such treatments, mostly concentrating on imaging technologies used in conjunction with image analysis. In addition, we introduce spectroscopic imaging techniques and fluorescence spectrophotometry as tools to assess the biochemical state of the hair fiber as a result of hair shape modification regimens. Finally, we demonstrate how the structural integrity of the fiber is monitored with dynamic scanning calorimetry and traditional mechanical testing of the tensile properties of hair.

  8. [Combination of successive free transplants and osseointegrated implants in the reconstruction of the upper jaw].

    PubMed

    Darche, V; Lejuste, P; Piette, E

    1998-11-01

    Various free flap transfers can be associated to reconstruct a defect after resections in the head and neck region. The use of these flaps can be synchronous (one-stage surgery) or metachronous (two-stage surgery) in order to correct or improve secondary residual deformities. A two-stage use of free flaps, first with an osteocutaneous scapular flap and second with a fascial radial forearm flap, is reported after total maxillectomy. The osteocutaneous scapular flap was used to restore function (swallowing, chewing, speech and cheek projection) and the radial forearm flap to improve esthetic facial morphology. Minor ancillary procedures were subsequently necessary to achieve the final result (brow lift, tarsal straightening and facial lift).

  9. Gaussian blurring-invariant comparison of signals and images.

    PubMed

    Zhang, Zhengwu; Klassen, Eric; Srivastava, Anuj

    2013-08-01

    We present a Riemannian framework for analyzing signals and images in a manner that is invariant to their level of blurriness, under Gaussian blurring. Using a well known relation between Gaussian blurring and the heat equation, we establish an action of the blurring group on image space and define an orthogonal section of this action to represent and compare images at the same blur level. This comparison is based on geodesic distances on the section manifold which, in turn, are computed using a path-straightening algorithm. The actual implementations use coefficients of images under a truncated orthonormal basis and the blurring action corresponds to exponential decays of these coefficients. We demonstrate this framework using a number of experimental results, involving 1D signals and 2D images. As a specific application, we study the effect of blurring on the recognition performance when 2D facial images are used for recognizing people.

  10. Thoracic endovascular aortic repair of a severely angulated aorta using a double-wire technique

    PubMed Central

    Kawatani, Yohei; Nakamura, Yoshitsugu; Hayashi, Yujiro; Taneichi, Tetsuyoshi; Ito, Yujiro; Kurobe, Hirotsugu; Suda, Yuji; Hori, Takaki

    2016-01-01

    When endovascular treatment is performed, angulation of the access route for a device can make the operative procedure difficult. We encountered a case in which we successfully completed thoracic endovascular aortic repair (TEVAR) in a patient with severely angulated aorta by applying ‘double-wire technique’. The patient was an 80-year-old woman. An aneurysm with a 71-mm diameter was observed in the descending aorta. We performed TEVAR. Device delivery could not be achieved by a conventional procedure using one guide wire since the peripheral aorta was severely angulated. Therefore, in addition to a guide wire for main body, a stiff wire and a stiff sheath were introduced to straighten the angulation. The device was successfully introduced and TEVAR was completed. We used the Relay Plus® that facilitates tracking through the angulation. The device has a dual structure consisting of a hard sheath and a flexible sheath. We performed TEVAR successfully. PMID:27421301

  11. The wire anchor loop traction (WALT) maneuver.

    PubMed

    Effendi, Khaled; Sacho, Raphael Hillel; Belzile, François; Marotta, Thomas R

    2015-01-23

    Crossing the neck of large complex intracranial aneurysms for the purposes of stent deployment can be challenging using standard over the wire techniques. We describe a novel yet simple technique for straightening out the loop formed within a large intracranial aneurysm, which is often required in order to cross the aneurysm neck into the distal branch. Both the microcatheter and microwire are initially introduced into the distal vasculature, followed by withdrawal of the microwire to a point parallel to the distal exiting branch. The microcatheter and microwire are then gently withdrawn and a series of maneuvers to gradually reduce the loop is performed, obviating the need for distal purchase in the form of a stent, balloon, or coil, which have previously been described to maintain distal purchase.

  12. The wire anchor loop traction (WALT) maneuver.

    PubMed

    Effendi, Khaled; Sacho, Raphael Hillel; Belzile, François; Marotta, Thomas R

    2016-02-01

    Crossing the neck of large complex intracranial aneurysms for the purposes of stent deployment can be challenging using standard over the wire techniques. We describe a novel yet simple technique for straightening out the loop formed within a large intracranial aneurysm, which is often required in order to cross the aneurysm neck into the distal branch. Both the microcatheter and microwire are initially introduced into the distal vasculature, followed by withdrawal of the microwire to a point parallel to the distal exiting branch. The microcatheter and microwire are then gently withdrawn and a series of maneuvers to gradually reduce the loop is performed, obviating the need for distal purchase in the form of a stent, balloon, or coil, which have previously been described to maintain distal purchase.

  13. Twist- and Tension-Mediated Elastic Coupling between DNA-Binding Proteins

    NASA Astrophysics Data System (ADS)

    Koslover, Elena F.; Spakowitz, Andrew J.

    2009-05-01

    We study the effective interaction between DNA-binding proteins that arises from elastic stresses in the DNA when tension is applied. Using the wormlike chain model, we calculate the free energy cost of introducing multiple nearby bends in the DNA. We find that the bend deformation energy promotes aggregation to straighten the linker DNA, while twist resistance of the linker leads to damped oscillations in the coupling free energy between two proteins. We calculate the mean first encounter time for proteins sliding along DNA, indicating, in some cases, an optimal applied tension for protein assembly. Our results highlight the need to consider DNA twist even when no torsion is applied and the DNA ends are free to rotate. The variable-range oscillatory coupling between DNA-binding proteins may provide a versatile mechanism for tension-mediated gene regulation.

  14. Oblique septal crossbar graft for anterior septal angle reconstruction.

    PubMed

    Aziz, Zeeshan S; Brenner, Michael J; Putman, Harrison C

    2010-01-01

    Nasal septal deformity is a central feature of the crooked nose, contributing to functional and aesthetic problems. Straightening of the septum often requires resection, scoring, or incision of the septum--maneuvers that inevitably weaken the cartilaginous dorsal and caudal L-shaped struts, which together are known as the L-strut. Compromise of this L-strut predisposes to septal buckling, recurrent deviation, and saddle nose deformity. We describe our experience with the oblique septal crossbar, a structural graft that allows biomechanically sound anterior septal angle reconstruction during septorhinoplasty. The technique improves dorsal septal support and facilitates correction of the crooked nose. The open septorhinoplasty approach and swinging door maneuver are followed by placement of a diagonally oriented crossbar graft, obtained from cartilage or the perpendicular plate. The approach allows consistent midline correction and buttressing of the nasal dorsum, with no complications to date.

  15. Removal of a bent tibial intramedullary nail: a rare case report and review of the literature.

    PubMed

    Aggerwal, Sameer; Soni, Ashwani; Saini, Uttam-C; Gahlot, Nitesh

    2011-04-01

    Intramedullary interlocking nailing is a gold standard for treatment of tibial shaft fractures. Bending of a nail secondary to trauma is a rare complication, which may be encountered in healed or unhealed tibial shaft fractures. Removal of such bent nail is always a challenge. We reported this case to discuss various techniques for removal of bent nails and to share our experience in removing a bent tibial intramedullary nail in a 30-year-old man, who was admitted in our department with re-fracture of the right tibial shaft due to a roadside accident two years after the initial surgical treatment. The intramedullary nail, bent by 30 degrees and visible on anterioposterior as well as on lateral radiographs, was firstly weakened by partially cutting the convex wall, then straightened by applying external force, and finally removed by using the standard nail removal method.

  16. Micromechanical modeling of the epimysium of the skeletal muscles.

    PubMed

    Gao, Yingxin; Waas, Anthony M; Faulkner, John A; Kostrominova, Tatiana Y; Wineman, Alan S

    2008-01-01

    A micromechanical model has been developed to investigate the mechanical properties of the epimysium. In the present model, the collagen fibers in the epimysium are embedded randomly in the ground substance. Two parallel wavy collagen fibers and the surrounding ground substance are used as the repeat unit (unit cell), and the epimysium is considered as an aggregate of unit cells. Each unit cell is distributed in the epimysium with some different angle to the muscle fiber direction. The model allows the progressive straightening of the collagen fiber as well as the effects of fiber reorientation. The predictions of the model compare favorably against experiment. The effects of the collagen fiber volume fraction, collagen fiber waviness at the rest length and the mechanical properties of the collagen fibers and the ground substance are analyzed. This model allows the analysis of mechanical behavior of most soft tissues if appropriate experimental data are available.

  17. Aluminum alloy 6013 sheet for new U. S. Navy aircraft

    SciTech Connect

    Kaneko, R.S.; Bakow, L.; Lee, E.W. Naval Air Development Center, Warminster, PA )

    1990-05-01

    The recently developed aluminum alloy 6013-T6 has been selected for the fuselage skin and other applications on the U.S. Navy's P-7A airplane, in place of the traditional 2024-T3 clad sheet. Alloy 6013-T6 is naturally corrosion resistant, like the well-established alloy 6061, and hence is used unclad. Its fatigue strength, fatigue crack growth and fracture toughness compare favorably with 2024-T3. Replacement of alloy 2024 with alloy 6013 also reduces manufacturing costs for formed parts, because 6013 is readily formed in the T4 temper, then simply aged to T6, thus avoiding the costly heat treatments and straightening required for alloy 2024. 5 refs.

  18. Cerebral arteriopathy associated with Arg179His ACTA2 mutation

    PubMed Central

    Amans, Matthew R; Stout, Charles; Fox, Christine; Narvid, Jared; Hetts, Steven W; Cooke, Daniel L; Higashida, Randall T; Dowd, Christopher F; McSwain, Hugh; Halbach, Van V

    2013-01-01

    ACTA2 mutations have recently been shown to cause a multisystem smooth muscle dysfunction syndrome that may result in pediatric stroke. We report a case of ACTA2 mutation in a 3-year-old girl presenting with acute ischemic stroke and provide high resolution imaging of the cerebral arteries demonstrating novel findings of multiple tiny aneurysms (particularly in the posterior circulation), as well as the more characteristic imaging phenotype of straightened and narrowed proximal intracranial vessels, dilated cervical vessels and occlusion of the M1 MCA segment without lenticulostriate collateral formation. This newly identified disease should be added to the differential diagnosis of pediatric stroke and cerebral vasculopathy. Neuroradiologists, interventionalists, surgeons and neurologists should become familiar with this rare disease and its clinical sequelae. PMID:24293535

  19. Filters for cathodic arc plasmas

    DOEpatents

    Anders, Andre; MacGill, Robert A.; Bilek, Marcela M. M.; Brown, Ian G.

    2002-01-01

    Cathodic arc plasmas are contaminated with macroparticles. A variety of magnetic plasma filters has been used with various success in removing the macroparticles from the plasma. An open-architecture, bent solenoid filter, with additional field coils at the filter entrance and exit, improves macroparticle filtering. In particular, a double-bent filter that is twisted out of plane forms a very compact and efficient filter. The coil turns further have a flat cross-section to promote macroparticle reflection out of the filter volume. An output conditioning system formed of an expander coil, a straightener coil, and a homogenizer, may be used with the magnetic filter for expanding the filtered plasma beam to cover a larger area of the target. A cathodic arc plasma deposition system using this filter can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  20. Fukushima Nuclear Accident: Sticking to the facts, not to the political correctness

    NASA Astrophysics Data System (ADS)

    Ohska, Tokio

    2014-05-01

    The Fukushima Nuclear Reactor disaster of 2011 is still a continuing disaster three years later, although some experts have proclaimed the 4 reactors being already under control. It is surely an incredibly difficult task to properly terminate nuclear accidents. However, I should point out that the process of termination plan has been marred by too much of politics and business messing up a scientific approach to do it in a rational way. This blame must to go to both pro-nuclear and anti-nuclear power people. It makes me feel sad to see people not respecting science in executing such a difficult task. I shall list up where things went wrong with the hope that this kind of action, as I do here, would trigger people to get back to science to straighten out the execution process. I will show a few examples of published papers presenting the opinion that it is inappropriate what the Japanese government considers to be safe.

  1. Black women's hair: the main scalp dermatoses and aesthetic practices in women of African ethnicity *

    PubMed Central

    Tanus, Aline; Oliveira, Camila Caberlon Cruz; Villarreal, Delky Johanna Villarreal; Sanchez, Fernando Andres Vargas; Dias, Maria Fernanda Reis Gavazzoni

    2015-01-01

    Afro-ethnic hair is different from Caucasian and Asian hair and has unique features. Ethnic hair is more prone to certain conditions or diseases. Such diseases are not only related to the fragile inner structure of the hair, but also to the cultural habits of hairstyles that often exert traction forces upon the pilosebaceous follicle. Women with African hair subject their hair to chemical treatments such as hair straightening and relaxing, and thus modify the structure of their hair shaft, making it more susceptible to damage. For this reason, hair complaints are common among black women and represent a diagnostic challenge to the dermatologist, requiring a thorough clinical examination of the hair and scalp, and a detailed medical history of the patient. The purpose of this review is to warn of the potential side effects and sequelae related to hairstyles and hair treatments used by black women, and to highlight the major diseases that affect this ethnicity. PMID:26375213

  2. The role of septal surgery in management of the deviated nose.

    PubMed

    Foda, Hossam M T

    2005-02-01

    The deviated nose represents a complex cosmetic and functional problem. Septal surgery plays a central role in the successful management of the externally deviated nose. This study included 260 patients seeking rhinoplasty to correct external nasal deviations; 75 percent of them had various degrees of nasal obstruction. Septal surgery was necessary in 232 patients (89 percent), not only to improve breathing but also to achieve a straight, symmetrical, external nose as well. A graduated surgical approach was adopted to allow correction of the dorsal and caudal deviations of the nasal septum without weakening its structural support to the dorsum or nasal tip. The approach depended on full mobilization of deviated cartilage, followed by straightening of the cartilage and its fixation in the corrected position by using bony splinting grafts through an external rhinoplasty approach.

  3. [The crooked nose: correction of dorsal and caudal septal deviations].

    PubMed

    Foda, H M T

    2010-09-01

    The deviated nose represents a complex cosmetic and functional problem. Septal surgery plays a central role in the successful management of the externally deviated nose. This study included 800 patients seeking rhinoplasty to correct external nasal deviations; 71% of these suffered from variable degrees of nasal obstruction. Septal surgery was necessary in 736 (92%) patients, not only to improve breathing, but also to achieve a straight, symmetric external nose. A graduated surgical approach was adopted to allow correction of the dorsal and caudal deviations of the nasal septum without weakening its structural support to the nasal dorsum or nasal tip. The approach depended on full mobilization of deviated cartilage, followed by straightening of the cartilage and its fixation in the corrected position by using bony splinting grafts through an external rhinoplasty approach.

  4. Self-powered Real-time Movement Monitoring Sensor Using Triboelectric Nanogenerator Technology.

    PubMed

    Jin, Liangmin; Tao, Juan; Bao, Rongrong; Sun, Li; Pan, Caofeng

    2017-09-05

    The triboelectric nanogenerator (TENG) has great potential in the field of self-powered sensor fabrication. Recently, smart electronic devices and movement monitoring sensors have attracted the attention of scientists because of their application in the field of artificial intelligence. In this article, a TENG finger movement monitoring, self-powered sensor has been designed and analysed. Under finger movements, the TENG realizes the contact and separation to convert the mechanical energy into electrical signal. A pulse output current of 7.8 μA is generated by the bending and straightening motions of the artificial finger. The optimal output power can be realized when the external resistance is approximately 30 MΩ. The random motions of the finger are detected by the system with multiple TENG sensors in series. This type of flexible and self-powered sensor has potential applications in artificial intelligence and robot manufacturing.

  5. Improvement of the Chairs in Classrooms for Better Sitting Posture of Children

    NASA Astrophysics Data System (ADS)

    Ishihara, Keiko; Dake, Kazuo; Ishihara, Shigekazu

    2010-10-01

    We sought to improve the sitting postures of children studying in the classrooms of a primary school. We made the seat of a standard chair lower and attached a cushion designed by one of the authors. The cushion is cut at a 25° downward angle toward the legs to allow the users to support their weight with their feet and alleviate pressure on the underside of the thighs. We also lowered the desktop to below the height of children's elbows. Eighty-three children were given the new chairs and desks, and they were observed over 7 months. Around 10% of them voluntarily maintained good sitting postures; others straightened their postures when the teachers reminded them to do so.

  6. Turbulence and mechanism of resistance on spheres and cylinders

    NASA Technical Reports Server (NTRS)

    Ahlborn, FR

    1932-01-01

    The nature of turbulent flow through pipes and around obstacles is analyzed and illustrated by photographs of turbulence on screens and straighteners. It is shown that the reversal of flow and of the resistance law on spheres is not explainable by Prandtl's turbulence in the boundary layer. The investigation of the analogous phenomena on the cylinder yields a reversal of the total field of flow. The very pronounced changes in pressure distribution connected with it were affirmed by manometric measurements on spheres by Professor O. Krell. The reversal in a homogenous nonvortical flow is brought about by the advance of the stable arrangement of Karman's dead air vortices toward the test object and by the substitution of an alternatingly one-sided or rotating but stable vortex formation in place of the initially symmetrical formation. This also explains the marked variations of the models.

  7. The relevance of the first ribs of the El Sidrón site (Asturias, Spain) for the understanding of the Neandertal thorax.

    PubMed

    Bastir, Markus; García-Martínez, Daniel; Estalrrich, Almudena; García-Tabernero, Antonio; Huguet, Rosa; Ríos, Luis; Barash, Alon; Recheis, Wolfgang; de la Rasilla, Marco; Rosas, Antonio

    2015-03-01

    Reconstructing the morphology of the Neanderthal rib cage not only provides information about the general evolution of human body shape but also aids understanding of functional anatomy and energetics. Despite this paleobiological importance there is still debate about the nature and extent of variations in the size and shape of the Neandertal thorax. The El Sidrón Neandertals can be used to contribute to this debate, providing new costal remains ranging from fully preserved and undistorted ribs to highly fragmented elements. Six first ribs are particularly well preserved and offer the opportunity to analyze thorax morphology in Neandertals. The aims of this paper are to present this new material, to compare the ontogenetic trajectories of the first ribs between Neandertals and modern humans, and, using geometric morphometrics, to test the hypothesis of morphological integration between the first rib and overall thorax morphology. The first ribs of the El Sidrón adult Neandertals are smaller in centroid size and tend to be less curved when compared with those of modern humans, but are similar to Kebara 2. Our results further show that the straightening of the first ribs is significantly correlated with a straightening of the ribs of the upper thorax (R = 0.66; p < 0.0001) in modern humans, suggesting modularity in the upper and lower thorax units as reported in other hominins. It also supports the hypothesis that the upper thorax of Neandertals differs in shape from modern humans with more anteriorly projecting upper ribs during inspiration. These differences could have biomechanical consequences and account for stronger muscle attachments in Neandertals. Different upper thorax shape would also imply a different spatial arrangement of the shoulder girdle and articulation with the humerus (torsion) and its connection to the upper thorax. Future research should address these inferences in the context of Neandertal overall body morphology.

  8. Collagen Matrix Remodeling in Stented Pulmonary Arteries after Transapical Heart Valve Replacement

    PubMed Central

    Ghazanfari, Samaneh; Driessen-Mol, Anita; Hoerstrup, Simon P.; Baaijens, Frank P.T.; Bouten, Carlijn V.C.

    2016-01-01

    The use of valved stents for minimally invasive replacement of semilunar heart valves is expected to change the extracellular matrix and mechanical function of the native artery and may thus impair long-term functionality of the implant. Here we investigate the impact of the stent on matrix remodeling of the pulmonary artery in a sheep model, focusing on matrix composition and collagen (re)orientation of the host tissue. Ovine native pulmonary arteries were harvested 8 (n = 2), 16 (n = 4) and 24 (n = 2) weeks after transapical implantation of self-expandable stented heart valves. Second harmonic generation (SHG) microscopy was used to assess the collagen (re)orientation of fresh tissue samples. The collagen and elastin content was quantified using biochemical assays. SHG microscopy revealed regional differences in collagen organization in all explants. In the adventitial layer of the arterial wall far distal to the stent (considered as the control tissue), we observed wavy collagen fibers oriented in the circumferential direction. These circumferential fibers were more straightened in the adventitial layer located behind the stent. On the luminal side of the wall behind the stent, collagen fibers were aligned along the stent struts and randomly oriented between the struts. Immediately distal to the stent, however, fibers on both the luminal and the adventitial side of the wall were oriented in the axial direction, demonstrating the stent impact on the collagen structure of surrounding arterial tissues. Collagen orientation patterns did not change with implantation time, and biochemical analyses showed no changes in the trend of collagen and elastin content with implantation time or location of the vascular wall. We hypothesize that the collagen fibers on the adventitial side of the arterial wall and behind the stent straighten in response to the arterial stretch caused by oversizing of the stent. However, the collagen organization on the luminal side suggests that

  9. Hydrologic-Hydraulic Modeling of Fluvial Sediment Transport During a Storm Event in a Highly Managed Watershed

    NASA Astrophysics Data System (ADS)

    Bressan, F.; Mantilla, R.

    2014-12-01

    Sediment movement along the main stem of a watershed is strongly affected by the sediment supply and the channel morphology. Anthropogenic interventions tend to alter the hydraulic conveyance and consequently modify the sediment regime of the main stem. This connection between channel hydraulics and sediment transport is often overlooked in hydrologic models where simplified methods are used for flow and sediment routing. In this study, we adopt a hydrologic-hydraulic modeling approach to quantify the fluvial sediment transport along the main stem of a watershed during a storm event. The hydrologic model CUENCAS is implemented to estimate the sub-hourly hydrographs of the major tributaries of the watershed. The simulated hydrographs are used as boundary conditions for the depth-averaged two-dimensional hydraulic model FESMWS to simulate the propagation of the flood wave along the main stem. The corresponding sub-hourly, unsteady non-equilibrium sediment transport along the main stem is also simulated with FESWMS. This procedure is applied to a highly managed agricultural watershed of Iowa. The study site has a catchment area of 70 Km2 with soils that are silty clay loams. The land-use is mostly row crop, but in the past decade a large portion of the watershed was converted to native prairie. The main stem is a meandering stream with a length of 15 Km and ten major tributaries contribute to its flow. Several sections of the main stem have been heavily channelized and straightened since the 1930s. Different grain size distributions and sediment boundary conditions are investigated to discern the effects of land-use changes and channelization on the sediment regime along the main stem. The simulations are able to capture the typical hysteresis between flow and sediment transport. The results indicate that the in-stream sediment transport rate is in general higher in the channelized sections and depends, to a certain extent, on the degree of straightening.

  10. A review of surgical strategies for penile prosthesis implantation in patients with Peyronie’s disease

    PubMed Central

    Anaissie, James

    2016-01-01

    The introduction of the inflatable penile prosthesis (IPP) has revolutionized the treatment of patients with both Peyronie’s disease (PD) and erectile dysfunction (ED). A thorough literature review was performed in order to review the surgical strategies used to treat PD, using the PubMed online database with the keywords “penile prosthesis”, “surgical management” and “Peyronie’s disease”. Patient satisfaction rates of 72–100% and partner satisfaction rates of 89% have been reported in the literature, although strong preoperative education may be needed to prepare patients for risks such as penile shortening, seen in up to 54% of patients. Three-piece IPPs are most commonly used, and when comparing the two most popular models (AMS 700 CX vs. Coloplast Titan), no significant differences were seen in functional outcomes or patient satisfaction. Simple insertion of an IPP has been shown to resolve curvature in 33–90% of patients, but surgeons may often need to also utilize ancillary straightening procedures for residual curvatures. Manual modeling can correct residual curvature with an 86–100% success rate, but with a 4% risk of urethral injury. When the post-modeling residual curvature exceeds 30 degrees, a plaque-releasing incision or plication is recommended to further reduce curvature. Grafting is recommended if the resulting incisional defect is larger than two centimeters. Alternative straightening techniques such as plication prior to IPP insertion, endoscopic plaque resection, the “scratch technique” and bone saw plaque incision have also been described. PMID:27298781

  11. Wingspan experience at Beijing Tiantan Hospital: new insights into the mechanisms of procedural complication from viewing intraoperative transient ischemic attacks during awake stenting for vertebrobasilar stenosis.

    PubMed

    Jiang, W-J; Yu, W; Du, B; Wong, E H C; Gao, F

    2010-06-01

    Intracranial vertebrobasilar artery (VBA) stenosis portends a stroke and death rate of 8.5-22.8% annually despite medical therapy. Stenting has emerged as a treatment option but also carries substantial risk. Awake stenting under local anesthesia to minimize major procedural complication was investigated. Between January 2007 and December 2008, 43 of 46 consecutive patients with severe symptomatic intracranial VBA stenosis underwent elective angioplasty assisted with self-expanding Wingspan stent under local anesthesia at our institute. All data were collected prospectively. All 43 patients tolerated the stenting procedure under local anesthesia well. Forty-two patients (97.7%) were stented successfully. Within 30 days, there were three periprocedural strokes, including thromboembolic infarct, pontine perforator infarct and intracranial hemorrhage, without fatality. In addition, five patients had intraoperative brainstem transient ischemic attacks (TIAs) seconds after the deployment of the stent delivery system across the tortuous VBA. The symptoms and signs included impaired consciousness (n=5), dysarthria (n=3), convulsion (n=2), conjugate horizontal gaze palsy (n=2), nystagmus (n=2) and pinpoint pupils (n=1). There was angiographic evidence of VBA straightening without thromboembolism. The TIAs resolved within minutes of prompt removal of the delivery catheter. VBA stenting under local anesthesia is feasible with a 7% periprocedural stroke risk. Awake stenting allows timely detection of intraoperative TIAs. The mechanism of intraoperative TIA appears to be stent delivery system induced VBA straightening and distortion of its vascular tree. A devastating stroke may ensue if the TIA is not detected and distortion of VBA perforators is not reversed promptly.

  12. No sweat: African American adolescent girls' opinions of hairstyle choices and physical activity.

    PubMed

    Woolford, Susan J; Woolford-Hunt, Carole J; Sami, Areej; Blake, Natalie; Williams, David R

    2016-01-01

    Obesity prevalence is higher among African American adolescent (AAA) girls than among non-black girls. Lower levels of physical activity (PA) likely contribute to this disparity; this may be impacted by hairstyle concerns. In 2011, focus groups were conducted with AAA girls 14-17 years old (n = 36) in Michigan (n = 9), California (n = 11), and Georgia (n = 16). Groups addressed perceptions of hairstyles, exercise, and relationships between the two. Groups were recorded, transcripts reviewed, and themes identified. Adolescents completed a standardized ethnic identity (EI) measure and a survey addressing demographics and PA. Linear regression was used to examine associations between self-reported activity and participants' characteristics. Four themes emerged: 1) between ages 8 and 15, when concerns about hairstyles began, participants changed from "juvenile" (natural) styles to "adult" (straightened) styles; 2) participants avoided getting wet or sweating during exercise because their straightened hair became "nappy;" 3) braids with extensions and natural styles were viewed as better for exercise but not very attractive; 4) participants almost universally selected long, straight hairstyles as most attractive. In Michigan and California, EI was positively associated with levels of PA (p < 0.05) and overall having extensions was also positively associated with levels of PA. A preference for straight hair may contribute to AAA girls avoiding certain activities due to concerns about sweat affecting their hair. Furthermore, EI and hairstyle choice appear to be associated with levels of PA for some participants. Efforts to increase AAA girls' PA may benefit from approaches that address hairstyle choices and EI.

  13. Computational Flow Analysis of a Left Ventricular Assist Device

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Kwak, Dochan; Benkowski, Robert

    1995-01-01

    Computational fluid dynamics has been developed to a level where it has become an Indispensable part of aerospace research and design. Technology developed foe aerospace applications am also be utilized for the benefit of human health. For example, a flange-to-flange rocket engine fuel-pump simulation includes the rotating and non-rotating components: the flow straighteners, the impeller, and diffusers A Ventricular Assist Device developed by NASA Johnson Space Center and Baylor College of Medicine has a design similar to a rocket engine fuel pump in that it also consists of a flow straightener, an impeller, and a diffuser. Accurate and detailed knowledge of the flowfield obtained by incompressible flow calculations can be greatly beneficial to designers in their effort to reduce the cost and improve the reliability of these devices. In addition to the geometric complexities, a variety of flow phenomena are encountered in biofluids Then include turbulent boundary layer separation, wakes, transition, tip vortex resolution, three-dimensional effects, and Reynolds number effects. In order to increase the role of Computational Fluid Dynamics (CFD) in the design process the CFD analysis tools must be evaluated and validated so that designers gain Confidence in their use. The incompressible flow solver, INS3D, has been applied to flow inside of a liquid rocket engine turbopump components and extensively validated. This paper details how the computational flow simulation capability developed for liquid rocket engine pump component analysis has bean applied to the Left Ventricular Assist Device being developed jointly by NASA JSC and Baylor College of Medicine.

  14. Polar ordering and structural distortion in electronic domain-wall properties of BiFeO3

    NASA Astrophysics Data System (ADS)

    Chen, Yun-Wen; Kuo, Jer-Lai; Chew, Khian-Hooi

    2017-08-01

    Bandgaps, band edges, and structural properties of domain walls (DWs) in multiferroic BiFeO3 (BFO) are studied using density functional theory. The ferroelectric DWs (namely, the 71°, 109°, and 180° DWs) in rhombohedral BFO are considered, with a view of critically examining the relationships between local bandgap, polar ordering, and octahedral distortion reported for this material. Our study reveals that the domain-wall electronic properties of BFO sensitively depend on the polarization behavior and structural distortion at the wall center. The value of the bandgap at the wall decreases with the weakening of ferroelectricity at the wall center. Compared to all the wall types, DWs with the paraelectric-like phase at the wall center exhibit a significantly reduced bandgap. The bandgap reduction is also found to be closely related to two key parameters of the octahedral distortion at the wall: Fe-O bonds and O-Fe-O angles. The reduction in the Fe-O bond deviation and the straightening in the O-Fe-O angles at the wall appear with a marked bandgap reduction in the BFO DWs. Such a structural change at BFO DWs is reminiscent of a cubic structure, which is consistent with the analysis of paraelectric-like behavior at DWs. However, our analysis reveals that the straightening of Fe-O-Fe does not have any obvious correlation with bandgap reduction as suggested in previous works. The influence of the octahedral distortion at DWs is further clarified by investigating the bandgap and structural properties of various BFO bulk phases including Pnma, Pna21, tetragonal (P4mm), and Amm2. Our result establishes important correlations between electronic properties, polar ordering, and structural distortion in BFO DWs. This study also suggests that photo nanocatalysts employing BFO DWs may be a promising strategy to enhance photocatalytic activity.

  15. Quantification of interaction and topological parameters of polyisoprene star polymers under good solvent conditions.

    PubMed

    Rai, Durgesh K; Beaucage, Gregory; Ratkanthwar, Kedar; Beaucage, Peter; Ramachandran, Ramnath; Hadjichristidis, Nikos

    2016-05-01

    Mass fractal scaling, reflected in the mass fractal dimension d_{f}, is independently impacted by topology, reflected in the connectivity dimension c, and by tortuosity, reflected in the minimum dimension d_{min}. The mass fractal dimension is related to these other dimensions by d_{f}=cd_{min}. Branched fractal structures have a higher mass fractal dimension compared to linear structures due to a higher c, and extended structures have a lower dimension compared to convoluted self-avoiding and Gaussian walks due to a lower d_{min}. It is found, in this work, that macromolecules in thermodynamic equilibrium display a fixed mass fractal dimension d_{f} under good solvent conditions, regardless of chain topology.  These equilibrium structures accommodate changes in chain topology such as branching c by a decrease in chain tortuosity d_{min}. Symmetric star polymers are used to understand the structure of complex macromolecular topologies. A recently published hybrid Unified scattering function accounts for interarm correlations in symmetric star polymers along with polymer-solvent interaction for chains of arbitrary scaling dimension. Dilute solutions of linear, three-arm and six-arm polyisoprene stars are studied under good solvent conditions in deuterated p-xylene. Reduced chain tortuosity can be viewed as steric straightening of the arms. Steric effects for star topologies are quantified, and it is found that steric straightening of arms is more significant for lower-molecular-weight arms. The observation of constant d_{f} is explained through a modification of Flory-Krigbaum theory for branched polymers.

  16. Curved bones: An adaptation to habitual loading.

    PubMed

    Milne, Nick

    2016-10-21

    Why are long bones curved? It has long been considered a paradox that many long bones supporting mammalian bodies are curved, since this curvature results in the bone undergoing greater bending, with higher strains and so greater fracture risk under load. This study develops a theoretical model wherein the curvature is a response to bending strains imposed by the requirements of locomotion. In particular the radioulna of obligate quadrupeds is a lever operated by the triceps muscle, and the bending strains induced by the triceps muscle counter the bending resulting from longitudinal loads acting on the curved bone. Indeed the theoretical model reverses this logic and suggests that the curvature is itself a response to the predictable bending strains induced by the triceps muscle. This, in turn, results in anatomical arrangements of bone, muscle and tendon that create a simple physiological mechanism whereby the bone can resist the bending due to the action of triceps in supporting and moving the body. The model is illustrated by contrasting the behaviour of a finite element model of a llama radioulna to that of a straightened version of the same bone. The results show that longitudinal and flexor muscle forces produce bending strains that effectively counter strains due to the pull of the triceps muscle in the curved but not in the straightened model. It is concluded that the curvature of these and other curved bones adds resilience to the skeleton by acting as pre-stressed beams or strainable pre-buckled struts. It is also proposed that the cranial bending strains that result from triceps, acting on the lever that is the radioulna, can explain the development of the curvature of such bones. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  17. A bi-hemispheric neuronal network model of the cerebellum with spontaneous climbing fiber firing produces asymmetrical motor learning during robot control

    PubMed Central

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2014-01-01

    To acquire and maintain precise movement controls over a lifespan, changes in the physical and physiological characteristics of muscles must be compensated for adaptively. The cerebellum plays a crucial role in such adaptation. Changes in muscle characteristics are not always symmetrical. For example, it is unlikely that muscles that bend and straighten a joint will change to the same degree. Thus, different (i.e., asymmetrical) adaptation is required for bending and straightening motions. To date, little is known about the role of the cerebellum in asymmetrical adaptation. Here, we investigate the cerebellar mechanisms required for asymmetrical adaptation using a bi-hemispheric cerebellar neuronal network model (biCNN). The bi-hemispheric structure is inspired by the observation that lesioning one hemisphere reduces motor performance asymmetrically. The biCNN model was constructed to run in real-time and used to control an unstable two-wheeled balancing robot. The load of the robot and its environment were modified to create asymmetrical perturbations. Plasticity at parallel fiber-Purkinje cell synapses in the biCNN model was driven by error signal in the climbing fiber (cf) input. This cf input was configured to increase and decrease its firing rate from its spontaneous firing rate (approximately 1 Hz) with sensory errors in the preferred and non-preferred direction of each hemisphere, as demonstrated in the monkey cerebellum. Our results showed that asymmetrical conditions were successfully handled by the biCNN model, in contrast to a single hemisphere model or a classical non-adaptive proportional and derivative controller. Further, the spontaneous activity of the cf, while relatively small, was critical for balancing the contribution of each cerebellar hemisphere to the overall motor command sent to the robot. Eliminating the spontaneous activity compromised the asymmetrical learning capabilities of the biCNN model. Thus, we conclude that a bi

  18. Ex Vivo Comparison of Mtwo and RaCe Rotary File Systems in Root Canal Deviation: One File Only versus the Conventional Method

    PubMed Central

    Aminsobhani, Mohsen; Nozari, Solmaz

    2015-01-01

    Objectives: Cleaning and shaping of the root canal system is an important step in endodontic therapy. New instruments incorporate new preparation techniques that can improve the efficacy of cleaning and shaping. The aim of this study was to compare the efficacy of Mtwo and RaCe rotary file systems in straightening the canal curvature using only one file or the conventional method. Materials and Methods: Sixty mesial roots of extracted human mandibular molars were prepared by RaCe and Mtwo nickel-titanium (NiTi) rotary files using the conventional and only one rotary file methods. The working length was 18 mm and the curvatures of the root canals were between 15–45°. By superimposing x-ray images before and after the instrumentation, deviation of the canals was assessed using Adobe Photoshop CS3 software. Preparation time was recorded. Data were analyzed using three-way ANOVA and Tukey’s post hoc test. Results: There were no significant differences between RaCe and Mtwo or between the two root canal preparation methods in root canal deviation in buccolingual and mesiodistal radiographs (P>0.05). Changes of root canal curvature in >35° subgroups were significantly more than in other subgroups with smaller canal curvatures. Preparation time was shorter in one file only technique. Conclusion: According to the results, the two rotary systems and the two root canal preparation methods had equal efficacy in straightening the canals; but the preparation time was shorter in one file only group. PMID:26877736

  19. Rotor Re-Design for the SSME Fuel Flowmeter

    NASA Technical Reports Server (NTRS)

    Marcu, Bogdan

    1999-01-01

    The present report describes the process of redesigning a new rotor for the SSME Fuel Flowmeter. The new design addresses the specific requirement of a lower rotor speed which would allow the SSME operation at 1 15% rated power level without reaching a blade excitation by the wakes behind the hexagonal flow straightener upstream at frequencies close to the blade natural frequency. A series of calculations combining fleet flowmeters test data, airfoil fluid dynamics and CFD simulations of flow patterns behind the flowmeter's hexagonal straightener has led to a blade twist design alpha = alpha (radius) targeting a kf constant of 0.8256. The kf constant relates the fuel volume flow to the flowmeter rotor speed, for this particular value 17685 GPM at 3650 RPM. Based on this angle distribution, two actual blade designs were developed. A first design using the same blade airfoil as the original design targeted the new kf value only. A second design using a variable blade chord length and airfoil relative thickness targeted simultaneously the new kf value and an optimum blade design destined to provide smooth and stable operation and a significant increase in the blade natural frequency associated with the first bending mode, such that a comfortable margin could be obtained at 115% RPL. The second design is a result of a concurrent engineering process, during which several iterations were made in order to achieve a targeted blade natural frequency associated with the first bending mode of 1300 Hz. Water flow tests preliminary results indicate a kf value of 0.8179 for the f-irst design, which is within 1% of the target value. The second design rotor shows a natural frequency associated with the first bending mode of 1308 Hz, and a water-flow calibration constant of kf 0.8169.

  20. Use of inflatable penile prostheses AMS CX with momentary squeeze in a patient with Peyronie's disease after removal of two previously implanted penile prostheses.

    PubMed

    Vicini, Patrizio; De Marco, Ferdinando; Antonini, Gabriele; De Berardinis, Ettore; Giovannone, Riccardo; Pecoraro, Stefano; Azzarri, Luigi; Gentile, Vincenzo

    2014-03-28

    Peyronie's disease (PD) is a fibrotic wound-healing condition of the tunica albuginea that results in penile deformity, curvature, hinging, narrowing and shortening, penile pain, and in some cases, erectile dysfunction (ED). Surgery remains the gold standard treatment option, ensuring the faster and trustworthy treatment. For those patients who have erectile dysfunction and PD, penile prosthesis placement with straightening procedure is the best method to solve both diseases. The aim of this article is to present the use of hydraulic penile prostheses AMS CX with Momentary Squeeze associated with a complete isolation of the neurovascular bundle in a complex case after removal of two previously implanted prostheses in a man suffering from Peyronie's disease and erectile dysfunction. A 50 year-old patient underwent two previous prosthetic implants in another hospital. The first implantation was performed using an infrapubic approach followed by placement of a three-component hydraulic penile prosthesis. After six months the prosthesis was removed using an infra-pubic approach and two soft prosthesis Virilis II were implanted during the same surgery. One year after the second operation we implanted a hydraulic penile prosthesis AMS CX with Momentary Squeeze after complete isolation of the neurovascular bundle, fixing the two crural tips at the same level of albuginea of the two corpora cavernosa. Twelve months after surgery the penis was completely straight without penile shortening and the patient was fully satisfied with his sexual life. The procedure enabled a perfect alignment of the cylinders along the longitudinal axis and penile prosthetic symmetry to obtain a good penile rigidity and a perfect penile straightening.

  1. Comparison between AMS 700™ CX and Coloplast™ Titan inflatable penile prosthesis for Peyronie's disease treatment and remodeling: clinical outcomes and patient satisfaction.

    PubMed

    Chung, Eric; Solomon, Matthew; DeYoung, Ling; Brock, Gerald B

    2013-11-01

    The implantation of inflatable penile prosthesis (IPP) with simultaneous manual penile remodeling allows for men to undergo a single procedure aimed at correcting both the penile deformity/curvature and erectile dysfunction (ED). To evaluate the clinical outcomes and patient satisfaction in men with Peyronie's disease (PD) and ED who underwent AMS 700™ CX and the newer Coloplast™ Titan inflatable penile prosthesis (IPP) implant. Patient demographics, type of IPP, clinical outcomes, post-implant sexual characteristics, and overall patient satisfaction. A single-center retrospective review of clinical database and prospective telephone survey were conducted in all men with PD who underwent IPP between January 2006 and November 2010. A total of 138 patients with an average age of 57.7 (32 to 80) underwent AMS 700 CX (88 patients) and Coloplast Titans (50 patients) IPP implantation during the 5-year period. The majority of patients (91%) had only one IPP implantation. The IPP clinical outcomes include eight (6%) revision surgery for device malfunction and three (2%) device explantation for prosthesis infection. While there was no statistically significance in device survival between the two devices, the trend favored AMS 700 CX over Titan (5-year Kaplan-Meier estimates of mechanical survival were 91% vs. 87%, P>0.05) and both IPPs provided similar penile straightening without the need for revision surgery. Most men (79%) reported great satisfaction following CX or Titan implants with greater than two thirds of men reported greater self-confidence and 82% of patients would undergo the same operation again. AMS 700™ CX and Coloplast™ Titan IPP implantation and penile remodeling appeared to provide permanent penile straightening and high patient satisfaction without an increase risk of revision surgery. © 2012 International Society for Sexual Medicine.

  2. A bi-hemispheric neuronal network model of the cerebellum with spontaneous climbing fiber firing produces asymmetrical motor learning during robot control.

    PubMed

    Pinzon-Morales, Ruben-Dario; Hirata, Yutaka

    2014-01-01

    To acquire and maintain precise movement controls over a lifespan, changes in the physical and physiological characteristics of muscles must be compensated for adaptively. The cerebellum plays a crucial role in such adaptation. Changes in muscle characteristics are not always symmetrical. For example, it is unlikely that muscles that bend and straighten a joint will change to the same degree. Thus, different (i.e., asymmetrical) adaptation is required for bending and straightening motions. To date, little is known about the role of the cerebellum in asymmetrical adaptation. Here, we investigate the cerebellar mechanisms required for asymmetrical adaptation using a bi-hemispheric cerebellar neuronal network model (biCNN). The bi-hemispheric structure is inspired by the observation that lesioning one hemisphere reduces motor performance asymmetrically. The biCNN model was constructed to run in real-time and used to control an unstable two-wheeled balancing robot. The load of the robot and its environment were modified to create asymmetrical perturbations. Plasticity at parallel fiber-Purkinje cell synapses in the biCNN model was driven by error signal in the climbing fiber (cf) input. This cf input was configured to increase and decrease its firing rate from its spontaneous firing rate (approximately 1 Hz) with sensory errors in the preferred and non-preferred direction of each hemisphere, as demonstrated in the monkey cerebellum. Our results showed that asymmetrical conditions were successfully handled by the biCNN model, in contrast to a single hemisphere model or a classical non-adaptive proportional and derivative controller. Further, the spontaneous activity of the cf, while relatively small, was critical for balancing the contribution of each cerebellar hemisphere to the overall motor command sent to the robot. Eliminating the spontaneous activity compromised the asymmetrical learning capabilities of the biCNN model. Thus, we conclude that a bi

  3. Computational Flow Analysis of a Left Ventricular Assist Device

    NASA Technical Reports Server (NTRS)

    Kiris, Cetin; Kwak, Dochan; Benkowski, Robert

    1995-01-01

    Computational fluid dynamics has been developed to a level where it has become an Indispensable part of aerospace research and design. Technology developed foe aerospace applications am also be utilized for the benefit of human health. For example, a flange-to-flange rocket engine fuel-pump simulation includes the rotating and non-rotating components: the flow straighteners, the impeller, and diffusers A Ventricular Assist Device developed by NASA Johnson Space Center and Baylor College of Medicine has a design similar to a rocket engine fuel pump in that it also consists of a flow straightener, an impeller, and a diffuser. Accurate and detailed knowledge of the flowfield obtained by incompressible flow calculations can be greatly beneficial to designers in their effort to reduce the cost and improve the reliability of these devices. In addition to the geometric complexities, a variety of flow phenomena are encountered in biofluids Then include turbulent boundary layer separation, wakes, transition, tip vortex resolution, three-dimensional effects, and Reynolds number effects. In order to increase the role of Computational Fluid Dynamics (CFD) in the design process the CFD analysis tools must be evaluated and validated so that designers gain Confidence in their use. The incompressible flow solver, INS3D, has been applied to flow inside of a liquid rocket engine turbopump components and extensively validated. This paper details how the computational flow simulation capability developed for liquid rocket engine pump component analysis has bean applied to the Left Ventricular Assist Device being developed jointly by NASA JSC and Baylor College of Medicine.

  4. The effect of high temperature deformation on the hot ductility of niobium-microalloyed steel

    NASA Astrophysics Data System (ADS)

    Zarandi, Faramarz Mh

    Low hot ductility at the straightening stage of the steel continuous casting process, where the surface temperature ranges from 600 to 1200°C, is associated with transverse cracking on the billet surface. This is attributed to various microalloying elements, which are essential for the mechanical characteristics of the final products. Thermomechanical processing is a new approach to alleviate this problem. In this work, two grades of Nb-containing steel, one modified with B, were examined. In order to simulate the key parameters of continuous casting, specimens were melted in situ and subjected to thermal conditions similar to that occurring in a continuous casting mill. They were also deformed at different stages of the thermal schedule. Finally, the hot ductility was evaluated at the end of the thermal schedule, corresponding to the straightening stage in continuous casting at which the hot ductility problem occurs in the continuous casting process. The results showed that the presence of B is noticeably beneficial to the hot ductility. Failure mode analysis was performed and the mechanism of fracture was elaborated. As well, the potential mechanisms under which B can improve the hot ductility were proposed. Deformation during solidification (i.e. in the liquid + solid two phase region) led to a significant loss of hot ductility in both steels. By contrast, deformation in the delta-ferrite region, after solidification, was either detrimental or beneficial depending on the deformation start temperature. The hot ductility was considerably improved in the steel without B when deformation was applied during the delta → gamma transformation. The effect of such deformation on the other steel grade was not significant. Examination of the microstructure revealed that such improvement is related to a grain refinement in austenite. Therefore, the effect of deformation parameters was studied in detail and the optimum condition leading to the greatest improvement in the

  5. [Palliative tendon transfer for reanimation of the wrist and finger extension lag. Report of 14 transfers for radial nerve palsies and ten transfers for brachial plexus lesions].

    PubMed

    Bincaz, L E; Cherifi, H; Alnot, J Y

    2002-01-01

    This retrospective study is based on 23 males and one female, of an average age of 36.2 years that presented to us between 1982 and 2000 with an average follow up of 61 months, with fully established paralysis of wrist and fingers extension. Fourteen patients had isolated radial nerve palsy, while ten patients had brachial plexus lesions. 1) The tendon transfer for radial nerve palsy was: PT to ECRB, FCU to ED + EPL and PL to APL + EPB; 2) for brachial plexus injury, the tendon transfer was: PT (n = 4) or FDS III or IV (n = 5) to ECRB, FCU (n = 8) or FDS IV (n = 1) to ED + EPL, PL to APL + EPB and wrist arthrodesis with transfer of FDS IV to ED + EPL and PL to APL + EPB. The results were evaluated according to the degree of wrist movement, MP extension of long fingers, opening of first commissure, thumb opposition, grip power and the subjective evaluation of results. Concerning the radial nerve palsy: results are excellent in nine cases and good in one case. An active extension of the wrist of 38 degrees was obtained as well as MP extension of 0 degree with the wrist straightened. Thumb oppositioned was conserved (Kapandji = 8.2), opening of the first commissure 40 degrees and grip power was 20 kg. Concerning the brachial plexus lesions: results are excellent in five cases and good in the other five. An active wrist extension of 32 degrees was obtained, as well as MP extension deficit of 16 degrees with wrist straightened. Opposition was concerned (Kapandji = 7.2), opening of first commissure of 38 degrees and grip power of 13 kg. The functional results are satisfactory, but the analytic study shows some effect of tenodesis of MP extension.

  6. Influence of RCS on Al-3Mg and Al-3Mg-0.25Sc alloys

    NASA Astrophysics Data System (ADS)

    Bhovi, Prabhakar M.; Venkateswarlu, K.

    2016-02-01

    An influence of repetitive corrugation and straightening (RCS) was studied on Al-3Mg and Al-3Mg-0.25Sc alloys up to eight passes. Each pass consist of a corrugation and followed by straightening. This has resulted in introducing large plastic strain in sample, and thus led to formation of sub-micron grain sizes with high angle grain boundaries. These sub grain formation was eventually resulted in improved mechanical properties. The average grain size of Al-3Mg-0.25Sc alloy after 8 passes yielded to ∼0.6pm. Microhardness, strength properties were evaluated and it suggests that RCS was responsible for high hardness values as compared to the as cast samples. The microhardness values after RCS were 105 HV and 130 HV for Al-3Mg and Al-3Mg-0.25Sc alloys, respectively. Similarly, ∼ 40% improvement in tensile strength from 240 MPa to 370 MPa was observed for Al- 3Mg-0.25Sc alloy after RCS process.Al-3Mg and Al-3Mg-0.25Scalloys exhibited maximum strength of 220 MPa and 370 MPa, respectively. It is concluded that RCS process has a strong influence on Al- 3Mg and Al-3Mg-0.25Sc alloys for obtaining improved mechanical properties and grain refinement. In addition to RCS process and presence of AESc precipitates in Al-3Mg-0.25Sc alloy had a significant role in grain refinement and improved mechanical properties as compared to Al-3Mg alloy.

  7. Collagen Matrix Remodeling in Stented Pulmonary Arteries after Transapical Heart Valve Replacement.

    PubMed

    Ghazanfari, Samaneh; Driessen-Mol, Anita; Hoerstrup, Simon P; Baaijens, Frank P T; Bouten, Carlijn V C

    2016-01-01

    The use of valved stents for minimally invasive replacement of semilunar heart valves is expected to change the extracellular matrix and mechanical function of the native artery and may thus impair long-term functionality of the implant. Here we investigate the impact of the stent on matrix remodeling of the pulmonary artery in a sheep model, focusing on matrix composition and collagen (re)orientation of the host tissue. Ovine native pulmonary arteries were harvested 8 (n = 2), 16 (n = 4) and 24 (n = 2) weeks after transapical implantation of self-expandable stented heart valves. Second harmonic generation (SHG) microscopy was used to assess the collagen (re)orientation of fresh tissue samples. The collagen and elastin content was quantified using biochemical assays. SHG microscopy revealed regional differences in collagen organization in all explants. In the adventitial layer of the arterial wall far distal to the stent (considered as the control tissue), we observed wavy collagen fibers oriented in the circumferential direction. These circumferential fibers were more straightened in the adventitial layer located behind the stent. On the luminal side of the wall behind the stent, collagen fibers were aligned along the stent struts and randomly oriented between the struts. Immediately distal to the stent, however, fibers on both the luminal and the adventitial side of the wall were oriented in the axial direction, demonstrating the stent impact on the collagen structure of surrounding arterial tissues. Collagen orientation patterns did not change with implantation time, and biochemical analyses showed no changes in the trend of collagen and elastin content with implantation time or location of the vascular wall. We hypothesize that the collagen fibers on the adventitial side of the arterial wall and behind the stent straighten in response to the arterial stretch caused by oversizing of the stent. However, the collagen organization on the luminal side suggests that

  8. Man-induced channel adjustment in Tennessee streams

    USGS Publications Warehouse

    Robbins, C.H.; Simon, Andrew

    1983-01-01

    Channel modifications in Tennessee, particularly in the western part, have led to large-scale instabilities in the channelized rivers and may have contributed to several bridge failures. These modifications, together with land-use practices, led to downcutting, headward erosion, downstream aggradation, accelerated scour, and bank instabilities. Changes in gradient by channel straightening caused more severe channel response than did dredging or clearing. Large-scale changes continue to occur in all the channelized rivers: the Obion River, its forks, and the South Fork Forked Deer River. However, the non-channelized Hatchie River in west Tennessee not only withstood the natural stresses imposed by the wet years of 1973 to 1975 but continues to exhibit characteristics of stability. Water-surface slope, the primary dependent variable, proved to be a sensitive and descriptive parameter useful in determining channel adjustment. Adjustments to man-induced increases in channel-slope are described by inverse exponential functions of the basic form S=ae(-b(t)); where ' S ' is some function describing channel-slope, ' t ' is the number of years since completion of channel work, and ' a ' and ' b ' are coefficients. Response times for the attainment of ' equilibrium ' channel slopes are a function of the magnitude and extent of the imposed modifications. The adjusted profile gradients attained by the streams following channelization are similar to the predisturbed profile gradients, where no alteration to channel length was made. Where the channels were straightened by constructing cut-offs, thus shortening channel length, then slope adjustments (reduction) proceed past the predisturbed profile gradients, to new profiles with lower gradients. (USGS)

  9. Surgical correction of persistent Peyronie's disease following collagenase clostridium histolyticum treatment.

    PubMed

    Levine, Laurence A; Larsen, Stephen M

    2015-01-01

    Collagenase clostridium histolyticum (CCH) is an Food and Drug Administration-approved intralesional injection for treatment of Peyronie's disease (PD) that has been shown to reduce penile curvature deformity and PD symptom bother in phase 2b and phase 3 placebo-controlled clinical trials. For some patients, nonsurgical treatment with CCH may not sufficiently improve penile curvature, and surgical correction may be pursued following CCH therapy. This study aims to examine intraoperative and postsurgical outcomes of surgical correction of persistent penile curvature in patients with PD who had previously received CCH. Retrospective chart review was used to identify patients with PD who had received CCH intralesional injection within either the phase 2b or phase 3 CCH clinical trials and then underwent surgical correction due to remaining penile curvature. Surgical techniques used were partial plaque excision and grafting (PEG) and/or tunica albuginea plication (TAP). Primary assessments included pre- and postsurgery penile curvature, erectile rigidity, stretched penile length, intraoperative time, and occurrence of adverse events. Seven men were identified who underwent surgical straightening with TAP or PEG following CCH treatment. Mean number of days from the final CCH injection to surgery was 182 (standard deviation 118; median 127 days). Average penile curvature prior to surgical straightening was 58°. No anatomical difficulties or complications secondary to the effects of prior CCH treatment occurred during surgery. Intraoperative time was representative of standard TAP and PEG surgeries (range 88-146 minutes). All men reported penile curvature <20° postsurgery. One patient experienced a postsurgery subgraft hematoma that required aspiration. There were no postsurgery reports of decreased penile sexual sensation and no occurrence of vascular compromise or decreased penile rigidity. This initial case series supports the hypothesis that prior CCH treatment is

  10. Radiographic Findings of Distressed Venous Stents and Inferior Vena Cava Filters: Clinical Implications.

    PubMed

    Chick, Jeffrey Forris Beecham; Abramowitz, Steven D; Osher, Matthew L; Khaja, Minhaj S; Cooper, Kyle J; Saad, Wael E; Williams, David M

    2017-08-31

    The objective of our study was to describe an association between the radiographic appearance of distressed intravascular implants and venous stenosis or occlusion and to determine the success of reparative endovascular procedures. Seventy-eight patients with distressed stents or inferior vena cava (IVC) filters characterized by pursing (short-axis contracture), straightening, longitudinal contraction (long-axis contracture), or fracture were identified from retrospective review of a venous registry for the period from February 2004 to October 2016. Patients originally presented with superior vena cava (SVC) syndrome (n = 25), arm swelling (n = 16), iliocaval thrombosis (n = 21), and lower extremity deep venous thrombosis (n = 16), and stents were initially placed in 65 and filters in 13. Implants were located in the IVC (n = 24), subclavian vein (n = 16), brachiocephalic vein (n = 15), common iliac vein (n = 10), multiple veins (n = 4), axillary vein (n = 4), common femoral vein (n = 3), SVC (n = 1), and internal jugular vein (n = 1). Implants included Wallstents in 63 patients; Smart stents in two patients; and Celect Platinum, Denali, Greenfield, and Trapease IVC filters in two, three, two, and six patients, respectively. Venographic indication, distress type, time from initial normal placement to identification of distress, venographic finding (patent, mild stenosis, high-grade stenosis, or occlusion), treatment, revascularization outcome, and complications were recorded. The mean time to distress was 23 months. Fifty-two (67%) patients underwent venography for symptoms and 26 (33%) for surveillance. Forty-five (58%) implants were pursed; 19 (24%), straightened; nine (12%), contracted; and five (6%), fractured. Venography depicted 48 (62%) high-grade stenoses, 19 (24%) complete occlusions, and six (8%) mild stenoses. Of the 73 patients who underwent an intervention, 29 (40%) underwent angioplasty, 15 (21%) underwent angioplasty and stenting, 15 (21%) underwent

  11. Suitability of air sampling locations downstream of bends and static mixing elements.

    PubMed

    McFarland, A R; Gupta, R; Anand, N K

    1999-12-01

    The revised standard for sampling effluent air from stacks and ducts of the nuclear industry places limits on the non-uniformity of velocity and contaminant profiles at the sampling location; namely, the coefficients of variation must not exceed 20% over an area that encompasses at least the center 2/3 of the cross sectional area. Tests were conducted to characterize the degree of mixing at downstream locations as affected by several types of flow disturbances, including 90 degree elbows and commercial static mixing devices. Flow straighteners were incorporated into the ducting upstream of the mixer to be tested to simulate the dampening of flow turbulence that might occur because of upstream HEPA filters. The coefficients of variation of velocity and tracer gas concentration measured in a straight tube at a distance of 3 diameters downstream from a 90 degree elbow were 17% and 69%, respectively. The mixing is impacted by the upstream flow turbulence. Without a flow straightener, the tracer gas concentration coefficient of variation was reduced to 33% at the 3-diameter location. The use of static mixing elements can greatly enhance the mixing process. A ring placed just downstream of a 90 degree elbow, which blocks the outer 56% of the cross sectional area, results in a coefficient of variation of 19% for tracer gas concentration at the 3-diameter location. Pressure loss across the elbow with the ring is about nine times that of the basic elbow. One of the commercially available static mixers provides coefficients of variation that are less than 10% for both velocity and tracer gas concentration at 4 diameters downstream from the mixer with a pressure loss that is only about 3.5 times as large as that of a 90 degree elbow.

  12. A unifying model for planform straightness of ripples and dunes in air and water

    USGS Publications Warehouse

    Rubin, David M.

    2012-01-01

    Geologists, physicists, and mathematicians have studied ripples and dunes for more than a century, but despite considerable effort, no general model has been proposed to explain perhaps the most fundamental property of their morphology: why are some bedforms straight, continuous, parallel, and uniform in planform geometry (i.e. two-dimensional) whereas others are irregular (three-dimensional)? Here we argue that physical coupling along the crest of a bedform is required to produce straight crests and that along-crest flow and sand transport provide effective physical mechanisms for that coupling. Ripples and dunes with the straightest and most continuous crests include longitudinal and oblique dunes in unidirectional flows, wave ripples, dunes in reversing flows, wind ripples, and ripples migrating along a slope. At first glance, these bedforms appear quite different (ripples and dunes; air and water; transverse, oblique, and longitudinal orientations relative to the net sand-transport direction), but they all have one property in common: a process that increases the amount of along-crest sand transport (that lengthens and straightens their crests) relative to the across-crest transport (that makes them migrate and take the more typical and more three-dimensional planform geometry). In unidirectional flows that produce straight bedforms, along-crest transport of sand is caused by along-crest flow (non-transverse bedform orientation), gravitational transport along an inclined crest, or ballistic splash in air. Bedforms in reversing flows tend to be straighter than their unidirectional counterparts, because reverse transport across the bedform crest reduces the net across-crest transport (that causes the more typical irregular geometry) relative to the along-crest transport (that smoothes and straightens planform geometry).

  13. Different coordination and flexibility of the spine and pelvis during lateral bending between young and older adults.

    PubMed

    Sung, Paul S

    2016-04-01

    This study examined coordination of the spine and pelvis during lateral bending of the trunk in older adults. Thirty-four healthy subjects (17 young and 17 older adults) demonstrated lateral bending at a controlled speed while holding a bar at approximately 180 degrees of shoulder flexion. Kinematic data collection was completed on the thoracic spine, lumbar spine, and pelvis. The coupling angle was calculated to examine the thorax-lumbar, lumbar-pelvis, and thorax-pelvis coordination patterns. The older adults demonstrated a reduced range of motion (ROM) of the lumbar spine, while both groups revealed similar ROM in the thorax and in the pelvis. The coupling angle between the straightening and bending phases was different only for the older adults in the thorax-lumbar (23.4±8.0 vs. -1.6±4.4, p=0.004) and the lumbar-pelvis (65.4±7.2 vs. 86.1±7.8, p=0.001) coordination. However, there was no group difference in the thorax-pelvis coordination. These findings indicate that age-related changes in the lumbar region affect coordination patterns only during the bending phase. The older adults preserved a similar pattern of movement to the young adults during the straightening phase, but the coordination variability of the coupling angles was greater for the older adults than for the young adults. This movement pattern suggests that the older adults lacked consistent trunk control in an attempt to optimize lateral bending coordination. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Quantifying measurement uncertainties in ADCP measurements in non-steady, inhomogeneous flow

    NASA Astrophysics Data System (ADS)

    Schäfer, Stefan

    2017-04-01

    The author presents a laboratory study of fixed-platform four-beam ADCP and three-beam ADV measurements in the tailrace of a micro hydro power setup with a 35kW Kaplan-turbine and 2.5m head. The datasets discussed quantify measurement uncertainties of the ADCP measurement technique coming from non-steady, inhomogeneous flow. For constant discharge of 1.5m3/s, two different flow scenarios were investigated: one being the regular tailrace flow downstream the draft tube and the second being a straightened, less inhomogeneous flow, which was generated by the use of a flow straightening device: A rack of diameter 40mm pipe sections was mounted right behind the draft tube. ADCP measurements (sampling rate 1.35Hz) were conducted in three distances behind the draft tube and compared bin-wise to measurements of three simultaneously measuring ADV probes (sampling rate 64Hz). The ADV probes were aligned horizontally and the ADV bins were placed in the centers of two facing ADCP bins and in the vertical under the ADCP probe of the corresponding depth. Rotating the ADV probes by 90° allowed for measurements of the other two facing ADCP bins. For reasons of mutual probe interaction, ADCP and ADV measurements were not conducted at the same time. The datasets were evaluated by using mean and fluctuation velocities. Turbulence parameters were calculated and compared as far as applicable. Uncertainties coming from non-steady flow were estimated with the normalized mean square error und evaluated by comparing long-term measurements of 60 minutes to shorter measurement intervals. Uncertainties coming from inhomogeneous flow were evaluated by comparison of ADCP with ADV data along the ADCP beams where ADCP data were effectively measured and in the vertical under the ADCP probe where velocities of the ADCP measurements were displayed. Errors coming from non-steady flow could be compensated through sufficiently long measurement intervals with high enough sampling rates depending on the

  15. Anthropogenic influences on hydrology and biota on the Glinščica stream

    NASA Astrophysics Data System (ADS)

    Koprivšek, M.

    2009-04-01

    As the size of the urban population was increasing, stream corridors have become more and more physically changed to ensure flood safety and to increase urban surfaces. For this purpose dams, accumulations, banks and other objects on the stream corridors have been built. Besides, riparian vegetation has been removed; river corridors have been straightened and often made of concrete. In comparison with natural streams, physically changed river corridors have different values of physical, chemical and biotic parameters, which influence self-purification capacity of the streams. We were investigating in which way these parameters were modified due to human influenced changes to river streams on five sampling sites on the Glinščica stream. For comparison we took another sampling site on its tributary Pržanec. First sampling site is located in almost unregulated reach, whereas the other four in regulated reach. Last two sampling sites are located in the reach with concrete channel. Depth of the river, water flow and velocity, composition of organic and inorganic substratum, temperature, dissolved oxygen, conductivity, pH, nitrates and phosphates were studied and also samples of periphyton and macroinvertebrates were taken in all four seasons from spring 2005 till winter 2006. We have found out that downstream water quality decreases with increase of human-caused changes on the stream corridor. Water quality decreases mostly for the insufficiency of shading, which leads to increased water temperature, increased saturation with oxygen and increased pH on sunny summer days. Straightened and concrete river channels cause decreased depth of the river, increased water flow and increased velocity. The main problem for water organisms regarding changing and straightening river channels is that substrate, velocities and depth become homogeneous. This means that there are no different habitats, suitable for different species and that there is no shelter to hide from high

  16. Development of a Methodology to Gather Seated Anthropometry in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Rajulu, Sudhakar; Young, Karen; Mesloh, Miranda

    2009-01-01

    The Constellation Program's Crew Exploration Vehicle (CEV) is required to accommodate the full population range of crewmembers according to the anthropometry requirements stated in the Human-Systems Integration Requirement (HSIR) document (CxP70024). Seated height is one of many critical dimensions of importance to the CEV designers in determining the optimum seat configuration in the vehicle. Changes in seated height may have a large impact to the design, accommodation, and safety of the crewmembers. Seated height can change due to elongation of the spine when crewmembers are exposed to microgravity. Spinal elongation is the straightening of the natural curvature of the spine and the expansion of inter-vertebral disks. This straightening occurs due to fluid shifts in the body and the lack of compressive forces on the spinal vertebrae. Previous studies have shown that as the natural curvature of the spine straightens, an increase in overall height of 3% of stature occurs which has been the basis of the current HSIR requirements. However due to variations in the torso/leg ratio and impact of soft tissue, data is nonexistent as to how spinal elongation specifically affects the measurement of seated height. In order to obtain this data, an experiment was designed to collect spinal elongation data while in a seated posture in microgravity. The purpose of this study was to provide quantitative data that represents the amount of change that occurs in seated height due to spinal elongation in microgravity environments. Given the schedule and budget constraints of ISS and Shuttle missions and the uniqueness of the problem, a methodology had to be developed to ensure that the seated height measurements were accurately collected. Therefore, simulated microgravity evaluations were conducted to test the methodology and procedures of the experiment. This evaluation obtained seat pan pressure and seated height data to a) ensure that the lap restraint provided sufficient

  17. Development of a Methodology to Gather Seated Anthropometry in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

    Rajulu, Sudhakar; Young, Karen; Mesloh, Miranda

    2009-01-01

    The Constellation Program's Crew Exploration Vehicle (CEV) is required to accommodate the full population range of crewmembers according to the anthropometry requirements stated in the Human-Systems Integration Requirement (HSIR) document (CxP70024). Seated height is one of many critical dimensions of importance to the CEV designers in determining the optimum seat configuration in the vehicle. Changes in seated height may have a large impact to the design, accommodation, and safety of the crewmembers. Seated height can change due to elongation of the spine when crewmembers are exposed to microgravity. Spinal elongation is the straightening of the natural curvature of the spine and the expansion of inter-vertebral disks. This straightening occurs due to fluid shifts in the body and the lack of compressive forces on the spinal vertebrae. Previous studies have shown that as the natural curvature of the spine straightens, an increase in overall height of 3% of stature occurs which has been the basis of the current HSIR requirements. However due to variations in the torso/leg ratio and impact of soft tissue, data is nonexistent as to how spinal elongation specifically affects the measurement of seated height. In order to obtain this data, an experiment was designed to collect spinal elongation data while in a seated posture in microgravity. The purpose of this study was to provide quantitative data that represents the amount of change that occurs in seated height due to spinal elongation in microgravity environments. Given the schedule and budget constraints of ISS and Shuttle missions and the uniqueness of the problem, a methodology had to be developed to ensure that the seated height measurements were accurately collected. Therefore, simulated microgravity evaluations were conducted to test the methodology and procedures of the experiment. This evaluation obtained seat pan pressure and seated height data to a) ensure that the lap restraint provided sufficient

  18. Magnetic Resonance Imaging of Optic Nerve Traction During Adduction in Primary Open-Angle Glaucoma With Normal Intraocular Pressure

    PubMed Central

    Demer, Joseph L.; Clark, Robert A.; Suh, Soh Youn; Giaconi, JoAnn A.; Nouri-Mahdavi, Kouros; Law, Simon K.; Bonelli, Laura; Coleman, Anne L.; Caprioli, Joseph

    2017-01-01

    Purpose We used magnetic resonance imaging (MRI) to ascertain effects of optic nerve (ON) traction in adduction, a phenomenon proposed as neuropathic in primary open-angle glaucoma (POAG). Methods Seventeen patients with POAG and maximal IOP ≤ 20 mm Hg, and 31 controls underwent MRI in central gaze and 20° to 30° abduction and adduction. Optic nerve and sheath area centroids permitted computation of midorbital lengths versus minimum paths. Results Average mean deviation (±SEM) was −8.2 ± 1.2 dB in the 15 patients with POAG having interpretable perimetry. In central gaze, ON path length in POAG was significantly more redundant (104.5 ± 0.4% of geometric minimum) than in controls (102.9 ± 0.4%, P = 2.96 × 10−4). In both groups the ON became significantly straighter in adduction (28.6 ± 0.8° in POAG, 26.8 ± 1.1° in controls) than central gaze and abduction. In adduction, the ON in POAG straightened to 102.0% ± 0.2% of minimum path length versus 104.5% ± 0.4% in central gaze (P = 5.7 × 10−7), compared with controls who straightened to 101.6% ± 0.1% from 102.9% ± 0.3% in central gaze (P = 8.7 × 10−6); and globes retracted 0.73 ± 0.09 mm in POAG, but only 0.07 ± 0.08 mm in controls (P = 8.8 × 10−7). Both effects were confirmed in age-matched controls, and remained significant after correction for significant effects of age and axial globe length (P = 0.005). Conclusions Although tethering and elongation of ON and sheath are normal in adduction, adduction is associated with abnormally great globe retraction in POAG without elevated IOP. Traction in adduction may cause mechanical overloading of the ON head and peripapillary sclera, thus contributing to or resulting from the optic neuropathy of glaucoma independent of IOP. PMID:28829843

  19. The Effect of Acoustic Disturbances on the Operation of the Space Shuttle Main Engine Fuel Flowmeter

    NASA Technical Reports Server (NTRS)

    Marcu, Bogdan; Szabo, Roland; Dorney, Dan; Zoladz, Tom

    2007-01-01

    The Space Shuttle Main Engine (SSME) uses a turbine fuel flowmeter (FFM) in its Low Pressure Fuel Duct (LPFD) to measure liquid hydrogen flowrates during engine operation. The flowmeter is required to provide accurate and robust measurements of flow rates ranging from 10000 to 18000 GPM in an environment contaminated by duct vibration and duct internal acoustic disturbances. Errors exceeding 0.5% can have a significant impact on engine operation and mission completion. The accuracy of each sensor is monitored during hot-fire engine tests on the ground. Flow meters which do not meet requirements are not flown. Among other parameters, the device is screened for a specific behavior in which a small shift in the flow rate reading is registered during a period in which the actual fuel flow as measured by a facility meter does not change. Such behavior has been observed over the years for specific builds of the FFM and must be avoided or limited in magnitude in flight. Various analyses of the recorded data have been made prior to this report in an effort to understand the cause of the phenomenon; however, no conclusive cause for the shift in the instrument behavior has been found. The present report proposes an explanation of the phenomenon based on interactions between acoustic pressure disturbances in the duct and the wakes produced by the FFM flow straightener. Physical insight into the effects of acoustic plane wave disturbances was obtained using a simple analytical model. Based on that model, a series of three-dimensional unsteady viscous flow computational fluid dynamics (CFD) simulations were performed using the MSFC PHANTOM turbomachinery code. The code was customized to allow the FFM rotor speed to change at every time step according to the instantaneous fluid forces on the rotor, that, in turn, are affected by acoustic plane pressure waves propagating through the device. The results of the simulations show the variation in the rotation rate of the flowmeter

  20. Computerized detection of vertebral compression fractures on lateral chest radiographs: Preliminary results with a tool for early detection of osteoporosis

    SciTech Connect

    Kasai, Satoshi; Li Feng; Shiraishi, Junji; Li Qiang; Doi, Kunio

    2006-12-15

    Vertebral fracture (or vertebral deformity) is a very common outcome of osteoporosis, which is one of the major public health concerns in the world. Early detection of vertebral fractures is important because timely pharmacologic intervention can reduce the risk of subsequent additional fractures. Chest radiographs are used routinely for detection of lung and heart diseases, and vertebral fractures can be visible on lateral chest radiographs. However, investigators noted that about 50% of vertebral fractures visible on lateral chest radiographs were underdiagnosed or under-reported, even when the fractures were severe. Therefore, our goal was to develop a computerized method for detection of vertebral fractures on lateral chest radiographs in order to assist radiologists' image interpretation and thus allow the early diagnosis of osteoporosis. The cases used in this study were 20 patients with severe vertebral fractures and 118 patients without fractures, as confirmed by the consensus of two radiologists. Radiologists identified the locations of fractured vertebrae, and they provided morphometric data on the vertebral shape for evaluation of the accuracy of detecting vertebral end plates by computer. In our computerized method, a curved search area, which included a number of vertebral end plates, was first extracted automatically, and was straightened so that vertebral end plates became oriented horizontally. Edge candidates were enhanced by use of a horizontal line-enhancement filter in the straightened image, and a multiple thresholding technique, followed by feature analysis, was used for identification of the vertebral end plates. The height of each vertebra was determined from locations of identified vertebral end plates, and fractured vertebrae were detected by comparison of the measured vertebral height with the expected height. The sensitivity of our computerized method for detection of fracture cases was 95% (19/20), with 1.03 (139/135) false

  1. Nonuniform elasticity of titin in cardiac myocytes: a study using immunoelectron microscopy and cellular mechanics.

    PubMed

    Granzier, H; Helmes, M; Trombitás, K

    1996-01-01

    Titin (also known as connectin) is a muscle-specific giant protein found inside the sarcomere, spanning from the Z-line to the M-line. The I-band segment of titin is considered to function as a molecular spring that develops tension when sarcomeres are stretched (passive tension). Recent studies on skeletal muscle indicate that it is not the entire I-band segment of titin that behaves as a spring; some sections are inelastic and do not take part in the development of passive tension. To better understand the mechanism of passive tension development in the heart, where passive tension plays an essential role in the pumping function, we investigated titin's elastic segment in cardiac myocytes using structural and mechanical techniques. Single cardiac myocytes were stretched by various amounts and then immunolabeled and processed for electron microscopy in the stretched state. Monoclonal antibodies that recognize different titin epitopes were used, and the locations of the titin epitopes in the sarcomere were studied as a function of sarcomere length. We found that only a small region of the I-band segment of titin is elastic; its contour length is estimated at approximately 75 nm, which is only approximately 40% of the total I-band segment of titin. Passive tension measurements indicated that the fundamental determinant of how much passive tension the heart develops is the strain of titin's elastic segment. Furthermore, we found evidence that in sarcomeres that are slack (length, approximately 1.85 microns) the elastic titin segment is highly folded on top of itself. Based on the data, we propose a two-stage mechanism of passive tension development in the heart, in which, between sarcomere lengths of approximately 1.85 microns and approximately 2.0 microns, titin's elastic segment straightens and, at lengths longer than approximately 2.0 microns, the molecular domains that make up titin's elastic segment unravel. Sarcomere shortening to lengths below slack

  2. Current surgical management of severe peyronie's disease.

    PubMed

    Perovic, Sava V; Djinovic, Rados P

    2010-11-01

    To report the principles of penile resculpturing of different deformities caused by M. Peyronie: restoration of penile length, girth and shape with or without penile prosthesis implantation. In the period between February 2007 and March 2009, we performed grafting surgery for M. Peyronie in 98 patients aged between 24 and 72 years (mean 52 years). Penile deformities were diferent: dorsal curvature in 54 (55%), lateral in 7 (7%), ventral in 11 (11%), and combined curvature in 21 (21%) associated corporal narrowing was present in 24 patients (24%). Four (4%) patients presented isolated penile shortening without other deformity. Isolated diffuse corporal narrowing without shortening was found in two (2%) patients. Severity of curvature ranges from 60 to 90 degrees, mean 72. Thirty one (31%) patients had associated ED. Surgical options for severe Peyronie's disease were: single grafting in 26 pts (26%), complex grafting including circular tunical incision in 36 pts (36%), and in patients with ED the same procedures combined with penile prosthesis implantation (37 pts, 38%). Surgical correction was based on measurement of the tunical defect and precise calculation of graft size and shape. Penile straightening and lengthening was achieved by equalizing of shortened penile side/s with the longest one (convex) and grafting. Penile width is reestablished with additional longitudinal incision/s and grafting; graft width is determined by measurement of difference in circumference between normal and narrowed part of the corpora. We used Intexen LP (AMS) as a grafting material in all cases. The mean follow-up was 15 months (6-25). Mean penile length gain without prosthesis was 2.8cm (1.5-4.2) and with prosthesis 3.2cm (2-4.5cm). Insuficient straightening was in 5 patients (>15 degree) where Neuro Vascular Bundle (NVB) was limiting factor. Twenty four patients reported hypoesthesia and reduced orgasmic sensitivity that recovered spontaneously after 3-6 months. De-novo ED

  3. Mechanosensitive Channel MscS in the Open State: Modeling of the Transition, Explicit Simulations, and Experimental Measurements of Conductance

    PubMed Central

    Anishkin, Andriy; Kamaraju, Kishore; Sukharev, Sergei

    2008-01-01

    Mechanosensitive channels of small conductance (MscS) are ubiquitous turgor pressure regulators found in many walled cells and some intracellular organelles. Escherichia coli MscS acting as a tension-activated osmolyte release valve shows a nonsaturable conductance (1.2 nS in a 39 mS/cm electrolyte) and weak preference for anions. Pursuing the transition pathways in this channel, we applied the extrapolated motion protocol (cycles of displacements, minimizations, and short simulations) to the previously generated compact resting conformation of MscS. We observed tilting and straightening of the kinked pore-forming TM3 helices during the barrel expansion. Extended all-atom simulations confirmed the stability of the open conformation in the bilayer. A 53° spontaneous axial rotation of TM3s observed after equilibration increased the width and polarity of the pore allowing for stable voltage-independent hydration and presence of both cations and anions throughout the pore. The resultant open state, characterized by a pore 1.6 nm wide, satisfied the experimental conductance and in-plane expansion. Applied transmembrane electric field (±100 to ±200 mV) in simulations produced a flow of both K+ and Cl−, with Cl− current dominating at higher voltages. Electroosmotic water flux strongly correlated with the chloride current (∼8 waters per Cl−). The selectivity and rectification were in agreement with the experimental measurements performed in the same range of voltages. Among the charged residues surrounding the pore, only K169 was found to contribute noticeably in the rectification. We conclude that (a) the barrel expansion involving tilting, straightening, and rotation of TM3s provides the geometry and electrostatics that accounts for the conductive properties of the open pore; (b) the observed regimen of ion passage through the pore is similar to electrodiffusion, thus macroscopic estimations closely approximate the experimental and molecular dynamics

  4. Peri- and intraarticular analgesia (PIA) superior to other procedures in TKA – review of literature and results of own RCT

    PubMed Central

    Beckmann, J.; Stathellis, A.; Fitz, W.; Köck, F.; Bauer, G.; Gebauer, M.; Schnurr, C.

    2016-01-01

    Background: TKA is a worldwide established surgery with periarticular infiltrations being scientifically funded is the superiority of in the perioperative setup of TKA nowadays. However, nerve blocks are still widely used as perioperative standard meaning possible analgesia beyond surger, but simultaneously with sensomotoric deficiency and resulting risk of fall as well as increased pain after removal of nerval catheters. Also a standard procedure is intubation which means immediate pain after awakening of patients with resulting need for sufficient oral, intravenous, intramuscular or subcutaneous analgesia. We present an actual review of the literature and an own RCT comparing infiltrations with nerve blocks, which to our best knowledge presents the first RCT combined with an additional continous part. Methods: Literature review (PubMed)Own RCT: 50 TKA were randomized and prospectively included. 25 patients received nerve blocks with a single ischiadicus block and a femoralis block with additional perineural catheter. 25 patients received periarticular infiltrations together with an intraarticular catheter (PIA). All catheters stayed for 4 days. Both groups received a laryngeal masc. Postoperative mobilisation, surgeon and type of prosthesis were the same in all patients. The following was evaluated pre- and postoperatively (first, third and sixth hour, first until sixth day): VAS, additional analgetics/ opioids, KSS score, knee function and ability to raise the straightened leg. Complications as infection, falls, DVT etc. were recorded. Results: Periarticular infiltrations are superior to other options in the perioperative setup of TKA which is clearly shown by literature (several studies including reviews) as well as the results of our own RCT: Pain occured in both groups, however, VAS, additional analgetics/ opioids and KSS score as well as the ability to raise the straightened leg were significantly better following PIA (p<0,01), with comparable knee function

  5. Computerized detection of vertebral compression fractures on lateral chest radiographs: preliminary results with a tool for early detection of osteoporosis.

    PubMed

    Kasai, Satoshi; Li, Feng; Shiraishi, Junji; Li, Qiang; Doi, Kunio

    2006-12-01

    Vertebral fracture (or vertebral deformity) is a very common outcome of osteoporosis, which is one of the major public health concerns in the world. Early detection of vertebral fractures is important because timely pharmacologic intervention can reduce the risk of subsequent additional fractures. Chest radiographs are used routinely for detection of lung and heart diseases, and vertebral fractures can be visible on lateral chest radiographs. However, investigators noted that about 50% of vertebral fractures visible on lateral chest radiographs were underdiagnosed or under-reported, even when the fractures were severe. Therefore, our goal was to develop a computerized method for detection of vertebral fractures on lateral chest radiographs in order to assist radiologists' image interpretation and thus allow the early diagnosis of osteoporosis. The cases used in this study were 20 patients with severe vertebral fractures and 118 patients without fractures, as confirmed by the consensus of two radiologists. Radiologists identified the locations of fractured vertebrae, and they provided morphometric data on the vertebral shape for evaluation of the accuracy of detecting vertebral end plates by computer. In our computerized method, a curved search area, which included a number of vertebral end plates, was first extracted automatically, and was straightened so that vertebral end plates became oriented horizontally. Edge candidates were enhanced by use of a horizontal line-enhancement filter in the straightened image, and a multiple thresholding technique, followed by feature analysis, was used for identification of the vertebral end plates. The height of each vertebra was determined from locations of identified vertebral end plates, and fractured vertebrae were detected by comparison of the measured vertebral height with the expected height. The sensitivity of our computerized method for detection of fracture cases was 95% (19/20), with 1.03 (139/135) false

  6. E-M shaped septal encircling with Medpor reconstruction on crooked noses: personal technique and postoperative results.

    PubMed

    Emsen, Ilteris Murat

    2008-01-01

    Correction of the crooked or deviated nose, a complex cosmetic and functional problem, is a challenge for the rhinoplasty surgeon. Although corrections using a wide range of surgical techniques to straighten the nose and maximize nasal function have been proposed, recurrence is very common because of cartilage memory and scar contracture. Therefore, to prevent recurrence and to maintain the correction of the septum, a stable, strong, and permanent support is needed with the ability to maintain its given shape after placement on one or both sides of the septum. For this purpose, the author planned to use a personally-shaped graft (EMSEN) with high-density porous polyethylene (Medpor, Porex Surgical Inc., Newnan, GA). In this study, the concept and technique of Medpor, composed of a nonresorbable alloplastic material for correction of the crooked nose, and the authors' experience using it, are presented. Currently, Medpor is readily available on the market as a thin plain sheet (0.85 x 38 x 50 mm) that can be cut to an appropriate size for our (EMSEN) grafts. Ingrowths of fibrous tissue inside and around Medpor stabilize the upper lateral cartilages and septum in their newly corrected position and maintain the corrected/straightened position. This material was used in 18 patients with crooked noses (7 with C-type and 11 with S-type noses). During a mean follow-up period of 20 months (range, 10-50 months), there were no complications, recurrences, or extrusions. Functional evaluation was performed using a visual analog scale before surgery and 6 months after surgery. Patients were asked to score their nasal breathing on a scale ranging from 0 to 100. The mean preoperative value was 17.78% +/- 1.23% (range, 15-25%), and the postoperative value was 86.67% +/- 1.21% (range, 80-95%). In conclusion, the use of EMSEN with Medpor grafts is a safe, effective, reliable, and permanent method for correction of the crooked nose. In the long term, the authors believe that EMSEN

  7. Design and analysis of rotor systems with multiple trailing edge flaps and resonant actuators

    NASA Astrophysics Data System (ADS)

    Kim, Jun-Sik

    The purpose of this thesis is to develop piezoelectric resonant actuation systems and new active control methods utilizing the multiple trailing-edge flaps' configuration for rotorcraft vibration suppression and blade loads control. An aeroelastic model is developed for a composite rotor blade with multiple trailing-edge flaps. The rotor blade airloads are calculated using quasi-steady blade element aerodynamics with a free wake model for rotor inflow. A compressible unsteady aerodynamics model is employed to accurately predict the incremental trailing edge flap airloads. Both the finite wing effect and actuator saturation for trailing-edge flaps are also included in an aeroelastic analysis. For a composite articulated rotor, a new active blade loads control method is developed and tested numerically. The concept involves straightening the blade by introducing dual trailing edge flaps. The objective function, which includes vibratory hub loads, bending moment harmonics and active flap control inputs, is minimized by an integrated optimal control/optimization process. A numerical simulation is performed for the steady-state forward flight of an advance ratio of 0.35. It is demonstrated that through straightening the rotor blade, which mimics the behavior of a rigid blade, both the bending moments and vibratory hub loads can be significantly reduced by 32% and 57%, respectively. An active vibration control method is developed and analyzed for a hingeless rotor. The concept involves deflecting each individual trailing-edge flap using a compact resonant actuation system. Each resonant actuation system could yield high authority, while operating at a single frequency. Parametric studies are conducted to explore the finite wing effect of trailing-edge flaps and actuator saturation. A numerical simulation has been performed for the steady-state forward flight (mu = 0.15 ˜ 0.35). It is demonstrated that multiple trailing-edge flap configuration with the resonant actuation

  8. Ultra-stretchable conductors based on buckled super-aligned carbon nanotube films

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Luo, Shu; Sun, Li; Wu, Yang; Jiang, Kaili; Li, Qunqing; Wang, Jiaping; Fan, Shoushan

    2015-05-01

    Ultra-stretchable conductors are fabricated by coating super-aligned carbon nanotube (SACNT) films on pre-strained polydimethylsiloxane (PDMS) substrates and forming buckled SACNT structures on PDMS after release of the pre-strain. The parallel SACNT/PDMS conductors demonstrate excellent stability with normalized resistance changes of only 4.1% under an applied strain as high as 200%. The SACNT/PDMS conductors prepared with cross-stacked SACNT films show even lower resistance variation. The parallel SACNT/PDMS conductors exhibit high durability with a resistance increase of less than 5% after 10 000 cycles at 150% strain. In situ microscopic observations demonstrate that the buckled SACNT structures are straightened during the stretching process with reversible morphology evolution and thus the continuous SACNT conductive network can be protected from fracture. Due to the excellent electrical and mechanical properties of SACNT films and the formation of the buckled structure, SACNT/PDMS films exhibit high stretchability and durability, possessing great potential for use as ultra-stretchable conductors for wearable electronics, sensors, and energy storage devices.Ultra-stretchable conductors are fabricated by coating super-aligned carbon nanotube (SACNT) films on pre-strained polydimethylsiloxane (PDMS) substrates and forming buckled SACNT structures on PDMS after release of the pre-strain. The parallel SACNT/PDMS conductors demonstrate excellent stability with normalized resistance changes of only 4.1% under an applied strain as high as 200%. The SACNT/PDMS conductors prepared with cross-stacked SACNT films show even lower resistance variation. The parallel SACNT/PDMS conductors exhibit high durability with a resistance increase of less than 5% after 10 000 cycles at 150% strain. In situ microscopic observations demonstrate that the buckled SACNT structures are straightened during the stretching process with reversible morphology evolution and thus the continuous

  9. Antimicrobial and Virulence-Modulating Effects of Clove Essential Oil on the Foodborne Pathogen Campylobacter jejuni

    PubMed Central

    Kovács, Judit K.; Felső, Péter; Makszin, Lilla; Pápai, Zoltán; Horváth, Györgyi; Ábrahám, Hajnalka; Palkovics, Tamás; Böszörményi, Andrea; Emődy, Levente

    2016-01-01

    ABSTRACT Our study investigated the antimicrobial action of clove (Syzygium aromaticum) essential oil (EO) on the zoonotic pathogen Campylobacter jejuni. After confirming the clove essential oil's general antibacterial effect, we analyzed the reference strain Campylobacter jejuni NCTC 11168. Phenotypic, proteomic, and transcriptomic methods were used to reveal changes in cell morphology and functions when exposed to sublethal concentrations of clove EO. The normally curved cells showed markedly straightened and shrunken morphology on the scanning electron micrographs as a result of stress. Although, oxidative stress, as a generally accepted response to essential oils, was also present, the dominance of a general stress response was demonstrated by reverse transcription-PCR (RT-PCR). The results of RT-PCR and two-dimensional (2D) PAGE revealed that clove oil perturbs the expression of virulence-associated genes taking part in the synthesis of flagella, PEB1, PEB4, lipopolysaccharide (LPS), and serine protease. Loss of motility was also detected by a phenotypic test. Bioautographic analysis revealed that besides its major component, eugenol, at least four other spots of clove EO possessed bactericidal activity against C. jejuni. Our findings show that clove EO has a marked antibacterial and potential virulence-modulating effect on C. jejuni. IMPORTANCE This study demonstrates that the components of clove essential oil influence not only the expression of general stress genes but also the expression of virulence-associated genes. Based on this finding, alternative strategies can be worked on to control this important foodborne pathogen. PMID:27520816

  10. Block model of western US kinematics from inversion of geodetic, fault slip, and earthquake data

    NASA Astrophysics Data System (ADS)

    McCaffrey, R.

    2003-12-01

    The active deformation of the southwestern US (30° to 41° N) is represented by a finite number of rotating, elastic spherical caps. Horizontal GPS velocities (1583), fault slip rates (94), and earthquake slip vectors (116) are inverted for block angular velocities, locking on block-bounding faults, and the rotation of individual GPS velocity fields relative to North America. GPS velocities are modeled as a combination of rigid block rotations and elastic strain rates resulting from interactions of adjacent blocks across bounding faults. The resulting Pacific - North America pole is indistinguishable from that of Beavan et al. (2001) and satisfies spreading in the Gulf of California and earthquake slip vectors in addition to GPS. The largest blocks, the Sierra Nevada - Great Valley and the eastern Basin and Range, show internal strain rates, after removing the elastic component, of only a few nanostrain/a, demonstrating long term approximately rigid behavior. Most fault slip data are satisfied except that the San Jacinto fault appears to be significantly faster than inferred from geology while the Coachella and San Bernardino segments of the San Andreas fault are slower, suggesting the San Andreas system is straightening out in Southern California. Vertical axis rotation rates for most blocks are clockwise and in magnitude more like the Pacific than North America. One exception is the eastern Basin and Range (242° E to 248° E) which rotates slowly anticlockwise about a pole offshore Baja.

  11. Finite Element Analysis of ECAP, TCAP, RUE and CGP Processes

    NASA Astrophysics Data System (ADS)

    Patil, Deepak C.; Kallannavar, Vinayak; Bhovi, Prabhakar M.; Kori, S. A.; Venkateswarlu, K.

    2016-02-01

    A finite element method was applied to study the various severe plastic deformation processes like, Equal Channel Angular Pressing (ECAP), Tubular Channel Angular Pressing (TCAP), Repetitive Upsetting and Extrusion (RUE) and Constrained Groove Pressing (CGP), considering aluminum AA-390 alloy as specimen material for all these processes. FEA simulation was carried out using AFDEX simulation tool. Effect of the various ECAP process parameters like, die corner angle, channel angle, and the coefficient of friction were analyzed. The die corner angles were divided into 2 equal parts for increasing the effectiveness of ECAP process, thereby increasing the channel number from 2 to 3 and further, their influence on ECAP process was investigated. A 3D simulation of TCAP was carried out for die shapes like triangular and trapezoidal, and variation of the generated stress and strain was plotted. In CGP, four cycle operation was carried out; wherein each cycle is composed of corrugating the specimen and subsequent straightening to original dimension. During RUE process, a maximum effective stress of 683.1 MPa was induced in the specimen after processing it for four complete cycles of RUE process; whereas the maximum strain induced during the same condition was 3.715.

  12. Identification of Land Cover in the Past Using Infrared Images at Present

    NASA Astrophysics Data System (ADS)

    Šafář, V.; Ždímal, V.

    2012-07-01

    Czech landscape is an old residential area used by humans since ancient times. People have influenced it since their arrival and various activities in different periods create landscape layers called a palimpsest. Land Cover of one location could have changed several times. The most important reason is meandering and subsequent straightening of rivers, deforestation, relocation and change in soil layers. These changes in the past affected the present management and it is important to identify them. A suitable tool for the determination of different sites is remote sensing in the infrared spectrum, which monitors changes in the vegetation with the support of archival materials. After identifying the different places you can search the archival materials, how the land cover looked in the past. There have been used these archival materials: maps II. and III. military mapping, basic maps and other maps and historical orthophotomap. Czech Republic has a national archive of aerial photographs with aerial photographs from the thirties of the last century maintained by MGHO Dobruska. A comparative analysis of Land Cover shows the increases and decreases in agricultural land, changes in communication line elements, forest losses and increases, comparing the legal and actual status of the forest boundaries and their changes over time, changes in the built areas and links to the surrounding countryside. Land Cover of this study was created primarily with a visual interpretation of each area with their vectorization and assigning attributes to these areas and then comparing each of archival materials.

  13. Tributary stream infiltration as a source of herbicides in an alluvial aquifer

    USGS Publications Warehouse

    Burkart, M.R.; Simpkins, W.W.; Squillace, P.J.; Helmke, M.

    1999-01-01

    Where Walnut Creek flows across the South Skunk River alluvial aquifer, it provides a potential source of herbicides and herbicide metabolites. This straightened reach of the creek loses water and dissolved contaminants to the alluvial aquifer through a layer of fine-grained flood plain deposits. Estimates of potential flux of chemicals were based on measurements taken during baseflow in April 1994 before herbicides were applied to the watershed and in June 1994 after chemical application and when stream discharge included runoff and tile-drainage water. Hydraulic head measurements between the creek and flood plain deposits and between the creek and aquifer confirmed the potential for downward groundwater flow during both sampling periods. Hydraulic conductivity estimates from slug tests were used to calculate an average linear groundwater velocity of 0.5 m d-1 in the fine- grained flood plain deposits. At this velocity, contaminants could be advectively transported to the aquifer within 6 d. The potential for atrazine (2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine) flux to the aquifer from the creek was estimated to be between 60 and 3000 ??g d-1 m-2. This rate is one to three orders of magnitude greater than the estimated flux via leaching beneath a typical field. If the process of vertical stream leakage occurs in many hydrologic settings, it may constitute a substantial source of herbicides to shallow alluvial aquifers in many areas of the Midwest.

  14. Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

    SciTech Connect

    Pollack, Brian R.

    1996-05-01

    Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 μm in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.

  15. Clinical predictors of time to return to competition following hamstring injuries.

    PubMed

    Guillodo, Yannick; Here-Dorignac, Caroline; Thoribé, Bertrand; Madouas, Gwénaelle; Dauty, Marc; Tassery, Francois; Saraux, Alain

    2014-07-01

    hamstring strain injuries are the most common sports-related muscle injuries and one of the main causes of missed sporting events. clinical findings reflecting hamstring injury severity at presentation predict time to sports resumption. cohort study (prognosis); Level of evidence, 2. five sports medicine specialists at four sports medicine centers prospectively evaluated 120 athletes within 5 days of acute hamstring injury. Patients were interviewed and asked to evaluate their worst pain on a visual analog scale (VAS). Four physical criteria were assessed at baseline: bruising, tenderness to palpation, pain upon isometric contraction, and pain upon passive straightening. The same standardized rehabilitation protocol was used in all patients. A standardized telephone interview was conducted 45 days after the injury to determine the time to-full recovery (≤40 days or >40 days). by univariate analysis, clinical criteria associated with a full recovery time >40 days were VAS pain score greater than 6, popping sound injury, pain during everyday activities for more than 3 days, bruising, and greater than 15° motion-range limitation. By multivariate analysis, only VAS pain score and pain during everyday activities were significantly associated with time to recovery >40 days (53% sensitivity, 95% specificity). the initial examination provides valuable information that can be used to predict the time to full recovery after acute hamstring injuries in athletes.

  16. Atraumatic Flexor tendon retrieval- a simple method

    PubMed Central

    2013-01-01

    Background Zone 2 flexor tendon injuries still represent a challenging problem to hand surgeons despite the well developed surgical techniques and suture materials. Meticulous surgical repair with atraumatic handling of the severed tendon stumps and minimal damage to the tendon sheath are particularly important to prevent postoperative adhesions and ruptures in this area. In zone 2 flexor tendon injuries proximal to the vinculas, the cut ends of the flexor tendons retract to the palm with muscle contraction. To retrieve the severed proximal flexor tendon under tendon sheath and pulley system is very difficult without damaging these structures. Many techniques are described in the literature for the delivery of the retracted proximal tendon stump to the repair site. Methods In this report we would like to present a simple and relatively atraumatic technique that facilitates passing of the retracted flexor tendon through the pulleys in zone 2. We sutured the proximal tendon stump at the distal palmar crease with 3–0 polypropylene suture and used a 14 gauge plastic feeding tube, acting like a conduit for the passage of straightened needle to the finger. Results We have used this technique 21 times without any complication in our clinic. We have not seen any suture breakage during the passage or needle breakage due to the bending of the needle. Conclusions We have found this technique is very simple and very effective in retrieving the retracted tendon stump without causing undue damage to the tendon stump or tendon sheath. PMID:24040913

  17. Graphite Composite Booms with Integral Hinges

    NASA Technical Reports Server (NTRS)

    Alexander, Wes; Carlos, Rene; Rossoni, Peter; Sturm, James

    2006-01-01

    A document discusses lightweight instrument booms under development for use aboard spacecraft. A boom of this type comprises a thin-walled graphite fiber/ matrix composite tube with an integral hinge that can be bent for stowage and later allowed to spring back to straighten the boom for deployment in outer space. The boom design takes advantage of both the stiffness of the composite in tubular geometry and the flexibility of thin sections of the composite. The hinge is formed by machining windows in the tube at diametrically opposite locations so that there remain two opposing cylindrical strips resembling measuring tapes. Essential to the design is a proprietary composite layup that renders the hinge tough yet flexible enough to be bendable as much as 90 in either of two opposite directions. When the boom is released for deployment, the torque exerted by the bent hinge suffices to overcome parasitic resistance from harnesses and other equipment, so that the two sections of the hinge snap to a straight, rigid condition in the same manner as that of measuring tapes. Issues addressed in development thus far include selection of materials, out-of-plane bending, edge cracking, and separation of plies.

  18. Panoramic ultrasound to measure in vivo tendo Achilles strain.

    PubMed

    Stokes, Oliver M; Theobald, Peter S; Pugh, Neil D; Nokes, Leonard D M

    2010-10-01

    The tendo Achilles (TA) is a tendon very susceptible to injury. Biomechanical methodologies for exploring tendon strain are limited, however, as they are typically performed in vitro or by indirectly measuring the displacement of reference markers. By using panoramic ultrasound, this study reports a novel approach to acquire direct, in vivo tendon extension data. Sonographic scans were acquired between two in vivo landmarks following a consistent pathway along the long axis of the distal TA. Ten subjects were scanned with an unloaded tendon and then when resisting a range of loads. Tendon cross-sectional area was measured following coronal scans of the TA in three subjects, allowing for calculation and plotting of stress versus strain. Coefficients of variation were also calculated to measure the reliability and robustness of the protocol. Data from all ten subjects were found to fit with classic tendon force versus extension trend. The stress versus strain plot indicated that the wavy collagen fibers were fully straightened at 4% to 6% strain, which is comparable to results reported in other studies. The Young's modulus of 0.5 to 2.1 GPa also compared favorably to published data. Coefficients of variation indicated that the protocol was repeatable, although the technique for measuring cross-sectional area could be improved. As the reported data is comparable to previous invasive and in vitro studies, we believe sports medicine specialists and orthopaedic surgeons can utilize panoramic ultrasound to directly measure in vivo tendon strain.

  19. A new technic for segmental spinal osteosynthesis using the posterior approach.

    PubMed

    Cotrel, Y; Dubousset, J

    2014-02-01

    The authors have designed a new method of instrumentation aimed at obtaining surgical fixation of the scoliotic curve without any postoperative external immobilisation. It is particularly strong and rigid and allows adequate reduction of the curve. This technique avoids the sublaminar space and thus prevents excessive blood loss and diminishes the danger of cord damage. The instrumentation is made of two parallel rough cylindrical rods inserted independently in the convexity and concavity of the curve. If necessary, they can be bent pre-operatively. They are attached to hooks placed on the laminae or pedicles, which are locked by bolts, thus allowing progressive straightening of the curve. They are joined by two transverse bars, one above and one below, to provide better rigidity to the device and to allow correction of rotation. The parts of the vertebrae left free by the device are denuded to allow the addition of grafts. Laboratory tests have demonstrated that this type of fixator is more rigid than the Harrington or Luque rods. Fifteen patients, either idiopathic or paralytic cases, were operated on without any neurological impairment. No loss of correction was observed since the hooks have been locked.

  20. "Accordion" deformity of a tortuous external iliac artery after stent-graft placement.

    PubMed

    Quinn, S F; Kim, J; Sheley, R C; Frankhouse, J H

    2001-02-01

    To identify a complication of endograft deployment in aneurysmal iliac arteries. A 71-year-old man was referred for endovascular treatment of a 60-mm-diameter right common iliac artery aneurysm; however, deployment of a homemade covered stent (Palmaz-Schatz and polytetrafluoroethylene) induced shortening of the tortuous external iliac artery, causing an "accordion" deformity. The anomaly proved difficult to treat with serial Wallstent deployment, because the convolution tightened and migrated caudally with each stent deployed, threatening outflow. Finally, after 3 Wallstents were implanted, the contour of the external iliac artery was straight, and flow was unimpeded. However, 3 weeks later, the external iliac artery had recoiled to its original redundant appearance, but flow remained satisfactory. The aneurysm remains excluded, with satisfactory distal flow after 24 months. Implanting endografts in redundant, tortuous arterial segments may prove problematic, since induced straightening by the device precipitates kinking in the redundant system. Although treatment may be required in some situations, the vessels may return to a noncompressed state by removing the delivery system and guidewire.

  1. NASA Tech Briefs, April 2004

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Topics covered include: Analysis of SSEM Sensor Data Using BEAM; Hairlike Percutaneous Photochemical Sensors; Video Guidance Sensors Using Remotely Activated Targets; Simulating Remote Sensing Systems; EHW Approach to Temperature Compensation of Electronics; Polymorphic Electronic Circuits; Micro-Tubular Fuel Cells; Whispering-Gallery-Mode Tunable Narrow-Band-Pass Filter; PVM Wrapper; Simulation of Hyperspectral Images; Algorithm for Controlling a Centrifugal Compressor; Hybrid Inflatable Pressure Vessel; Double-Acting, Locking Carabiners; Position Sensor Integral with a Linear Actuator; Improved Electromagnetic Brake; Flow Straightener for a Rotating-Drum Liquid Separator; Sensory-Feedback Exoskeletal Arm Controller; Active Suppression of Instabilities in Engine Combustors; Fabrication of Robust, Flat, Thinned, UV-Imaging CCDs; Chemical Thinning Process for Fabricating UV-Imaging CCDs; Pseudoslit Spectrometer; Waste-Heat-Driven Cooling Using Complex Compound Sorbents; Improved Refractometer for Measuring Temperatures of Drops; Semiconductor Lasers Containing Quantum Wells in Junctions; Phytoplankton-Fluorescence-Lifetime Vertical Profiler; Hexagonal Pixels and Indexing Scheme for Binary Images; Finding Minimum-Power Broadcast Trees for Wireless Networks; and Automation of Design Engineering Processes.

  2. Evaluation of the Therapeutic Potential of a CNP Analog in a Fgfr3 Mouse Model Recapitulating Achondroplasia

    PubMed Central

    Lorget, Florence; Kaci, Nabil; Peng, Jeff; Benoist-Lasselin, Catherine; Mugniery, Emilie; Oppeneer, Todd; Wendt, Dan J.; Bell, Sean M.; Bullens, Sherry; Bunting, Stuart; Tsuruda, Laurie S.; O'Neill, Charles A.; Di Rocco, Federico; Munnich, Arnold; Legeai-Mallet, Laurence

    2012-01-01

    Achondroplasia (ACH), the most common form of dwarfism, is an inherited autosomal-dominant chondrodysplasia caused by a gain-of-function mutation in fibroblast-growth-factor-receptor 3 (FGFR3). C-type natriuretic peptide (CNP) antagonizes FGFR3 downstream signaling by inhibiting the pathway of mitogen-activated protein kinase (MAPK). Here, we report the pharmacological activity of a 39 amino acid CNP analog (BMN 111) with an extended plasma half-life due to its resistance to neutral-endopeptidase (NEP) digestion. In ACH human growth-plate chondrocytes, we demonstrated a decrease in the phosphorylation of extracellular-signal-regulated kinases 1 and 2, confirming that this CNP analog inhibits fibroblast-growth-factor-mediated MAPK activation. Concomitantly, we analyzed the phenotype of Fgfr3Y367C/+ mice and showed the presence of ACH-related clinical features in this mouse model. We found that in Fgfr3Y367C/+ mice, treatment with this CNP analog led to a significant recovery of bone growth. We observed an increase in the axial and appendicular skeleton lengths, and improvements in dwarfism-related clinical features included flattening of the skull, reduced crossbite, straightening of the tibias and femurs, and correction of the growth-plate defect. Thus, our results provide the proof of concept that BMN 111, a NEP-resistant CNP analog, might benefit individuals with ACH and hypochondroplasia. PMID:23200862

  3. Evaluation of the therapeutic potential of a CNP analog in a Fgfr3 mouse model recapitulating achondroplasia.

    PubMed

    Lorget, Florence; Kaci, Nabil; Peng, Jeff; Benoist-Lasselin, Catherine; Mugniery, Emilie; Oppeneer, Todd; Wendt, Dan J; Bell, Sean M; Bullens, Sherry; Bunting, Stuart; Tsuruda, Laurie S; O'Neill, Charles A; Di Rocco, Federico; Munnich, Arnold; Legeai-Mallet, Laurence

    2012-12-07

    Achondroplasia (ACH), the most common form of dwarfism, is an inherited autosomal-dominant chondrodysplasia caused by a gain-of-function mutation in fibroblast-growth-factor-receptor 3 (FGFR3). C-type natriuretic peptide (CNP) antagonizes FGFR3 downstream signaling by inhibiting the pathway of mitogen-activated protein kinase (MAPK). Here, we report the pharmacological activity of a 39 amino acid CNP analog (BMN 111) with an extended plasma half-life due to its resistance to neutral-endopeptidase (NEP) digestion. In ACH human growth-plate chondrocytes, we demonstrated a decrease in the phosphorylation of extracellular-signal-regulated kinases 1 and 2, confirming that this CNP analog inhibits fibroblast-growth-factor-mediated MAPK activation. Concomitantly, we analyzed the phenotype of Fgfr3(Y367C/+) mice and showed the presence of ACH-related clinical features in this mouse model. We found that in Fgfr3(Y367C/+) mice, treatment with this CNP analog led to a significant recovery of bone growth. We observed an increase in the axial and appendicular skeleton lengths, and improvements in dwarfism-related clinical features included flattening of the skull, reduced crossbite, straightening of the tibias and femurs, and correction of the growth-plate defect. Thus, our results provide the proof of concept that BMN 111, a NEP-resistant CNP analog, might benefit individuals with ACH and hypochondroplasia. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  4. CRYPTIC CHOICE OF CONSPECIFIC SPERM CONTROLLED BY THE IMPACT OF OVARIAN FLUID ON SPERM SWIMMING BEHAVIOR

    PubMed Central

    Yeates, Sarah E; Diamond, Sian E; Einum, Sigurd; Emerson, Brent C; Holt, William V; Gage, Matthew J G

    2013-01-01

    Despite evidence that variation in male–female reproductive compatibility exists in many fertilization systems, identifying mechanisms of cryptic female choice at the gamete level has been a challenge. Here, under risks of genetic incompatibility through hybridization, we show how salmon and trout eggs promote fertilization by conspecific sperm. Using in vitro fertilization experiments that replicate the gametic microenvironment, we find complete interfertility between both species. However, if either species’ ova were presented with equivalent numbers of both sperm types, conspecific sperm gained fertilization precedence. Surprisingly, the species’ identity of the eggs did not explain this cryptic female choice, which instead was primarily controlled by conspecific ovarian fluid, a semiviscous, protein-rich solution that bathes the eggs and is released at spawning. Video analyses revealed that ovarian fluid doubled sperm motile life span and straightened swimming trajectory, behaviors allowing chemoattraction up a concentration gradient. To confirm chemoattraction, cell migration tests through membranes containing pores that approximated to the egg micropyle showed that conspecific ovarian fluid attracted many more spermatozoa through the membrane, compared with heterospecific fluid or water. These combined findings together identify how cryptic female choice can evolve at the gamete level and promote reproductive isolation, mediated by a specific chemoattractive influence of ovarian fluid on sperm swimming behavior. PMID:24299405

  5. Influence of a vertical deviation of a 10-storey apartment building in Katowice, Poland, on selected mental functions of its occupants. A preliminary study.

    PubMed

    Kobza, Joanna; Pastuszka, Józef; Geremek, Mariusz; Gulis, Gabriel; Witecki, Kazimierz

    2013-01-01

    Coal exploitation technology could have affected the deformation of ground under a housing estate in the Upper Silesia agglomeration. The 10-storey apartment building began to deviate from the vertical. These factors affected the housing conditions of inhabitants in the block of flats. From 1991-2001, coal-mine surveyors monitored the vertical deviation. The inhabitants of the apartment building decided to put in a claim to their housing association which subsequently requested that the coal mine authorities repair the damages. The coal mine authorities initially refused to acknowledge inhabitants claim. An interdisciplinary group of experts were engaged who examined the group of inhabitants. Generally accepted and evidence based psychological methods were selected and certified, and psychological equipment was used. Preliminary deductions showed a strict connection between psychical discomfort, negative stress and vertical deviation. Based on the experts' report, the housing association decided to sue the coal mine authorities who offered to settle the inhabitants' grievances out of court and to straighten the apartment building - an influenced decision. This report is one of the best documented examples of a health impact assessment conducted in the 1990, a long time before the legal and methodological basis of Health Impact Assessment (HIA) and Environmental Impact Assessment (EIA) began to be implemented in other European countries.

  6. Loss of cervical lordosis: What is the prognosis?

    PubMed Central

    Lippa, Laura; Lippa, Luciano; Cacciola, Francesco

    2017-01-01

    Neck pain is a diffuse problem with a high incidence and often leads to the more or less appropriate prescription of imaging studies of the cervical spine. In general, this is represented by a magnetic resonance imaging (MRI) scan. Frequently such studies reveal no other significant findings apart from a loss of cervical lordosis either under the form of a simple straightening of the spine or even an inversion of the normal curvature into a kyphosis. Faced with this entity, the clinician is put in front of a series of questions: to which extent such a finding plays a role in the patient's symptoms? If it does what is the role of conservative or even invasive treatment? What are the implications for surgery either for decompressive procedures or corrective procedures? To shed some light on these questions, the authors present a narrative review of the most relevant literature on the topic. Papers examined span from the initial epidemiologic reports out of the pre-MRI and computerized tomography era up to the most recent discussions on cervical sagittal alignment and its implications both for the surgical and nonsurgical patient. In this process, it becomes increasingly clear that we are still far from making any definite statements. PMID:28250631

  7. Anatomy Of A Better Tip

    NASA Astrophysics Data System (ADS)

    Webster, Wilton W.

    1989-08-01

    We have developed a unique electrode catheter which combines a deflectable tip with a high torque shaft. The control handle is at the proximal end of the catheter. The control handle and the electrical connector which extends out the back of it are symmetrical about the catheter axis for optimum control. The tip deflects to the desired curve when a piston at the distal end of the handle is pushed forward by a thumb ring, and straightens again when the piston is pulled back. I will talk today about how we have developed this catheter. Although this may seem far afield from an SPIE subject, remember that any catheter used for transferring electrical or laser energy inside the body must have some rather unique properties. The tip or delivery end of the catheter must be placed and controlled correctly from outside the body two or three feet proximal from the tip. This catheter is used by cardiac electrophysiologists to study the electrical conduction system of the heart. During the past ten years the science of electrophysiology (EP) has seen major advances. But the tools of the trade, the catheters for performing the studies, have not significantly improved. Our deflectable tip catheter is indeed a significant advancement.

  8. Investigation on a free piston stirling cryocooler with large cooling capacity

    NASA Astrophysics Data System (ADS)

    Yu, G. Y.; Li, K.; Dai, W.; Luo, E. C.; Wu, Z. H.

    2014-01-01

    Cryocoolers with large cooling powers at 80 K are very promising as they could find important applications in superconducting field such as cooling cables, transformers and fault current limiters. The pulse tube cryocooler has attracted attention due to its virtue of no moving components in the cold region. However, as the cooling power increases, problems inside the thermal buffer tube, such as difficulty in obtaining good flow straightening, existence of Rayleigh streaming, the gravity effect etc., present big obstacles to achieving high thermal efficiency. On the other hand, a free piston Stirling cryocooler, though more complicated due to the existence of the displacer, could avoid these problems with the elimination of the thermal buffer tube. Meanwhile, the efficiency is better than the pulse tube cryocooler around 80 K due to its capability of recovering the acoustic work. In this article, a free piston Stirling cryocooler with about 300 W cooling power at 80 K is designed with our simulation based on thermoacoustic theory. The theoretical analysis and numeric model are given in detail. The phase shift effect of the displacer and the internal energy loss mechanism are discussed. From our calculation, a relative Carnot efficiency of about 50% at 80 K has been obtained analytically.

  9. Mathematical formulation of biomechanical parameters used in orthodontic treatment

    NASA Astrophysics Data System (ADS)

    Balakrishna, A.; Vamsi, Ch. Raghu; Rao, V. D. Prasad; Swamy, Ch. Kishore; Kuladeep, B.

    2015-05-01

    Orthodontic Treatment is being widely practiced around the world for teeth straightening and extraction to improve alignment of remaining teeth. Here, forces are applied to correct the position of teeth. The force applied on the teeth isn't calibrated and applied arbitrarily based on the recommendations from scientific research and experience of the orthodontist. The number of settings and the total time required for the completion of treatment also remains arbitrary. So, there is a need for determining the force which is actually acting on the teeth and determining the optimal force required for the treatment of each and every individual case. In this paper a mathematical relation is derived between the force applied on the tooth and tooth displacement by considering a 2nd order non-homogeneous linear differential equation. As the tooth displacement is not a direct function of force applied, Biomechanical parameters like mass of tooth, stiffness and damping coefficient of periodontal ligament & alveolar bone are involved in the differential equation. By solving the equation, tooth displacement thereby, tooth velocity can be obtained for a particular force. On the other hand, based on the dimensions of the model, orthodontist could determine the total tooth displacement required for each setting of the treatment, so that, the total displacement is covered. The orthodontist uses the data and applies the required force on to the teeth, based on which the orthodontist can plan his treatment procedure and reduce the number of settings, total treatment time and also increases the success rate of the treatment.

  10. Responses of Sesbania rostrata and S. cannabina to Pb, Zn, Cu and Cd toxicities.

    PubMed

    Yang, Zhong-yi; Chen, Fu-hua; Yuan, Jian-gang; Zheng, Zheng-wei; Wong, Ming-hung

    2004-01-01

    Responses of Sesbania rostrata and S. cannabina to Pb, Zn, Cu and Cd toxicities were assessed by a seed-suspending seedbed(SSS) approach. The results showed that the SSS approach was suitable for testing the tolerance of a plant to the stress of toxic metals. The endpoints include seed germination success, straightened radicle and hypocotyl of the seedlings from the seeds. The measurements could be done easily and accurately. It was found that the elongation of radicle was the most sensitive indicator to the stress of heavy metals among the endpoints. When exposure to lower or medium concentrations of Pb, Zn, and Cd, the development of the lateral roots were favorable. Species of S. rostrata was more tolerant than S. cannabina to the heavy metals, especially to Zn and Cd. The ED50 of Pb, Zn, Cu and Cd were 32.90, 5.32, 4.40 and 12.00 microg/ml for S. rostrata, respectively, and they were 30.11, 2.87, 4.05 and 4.94 microg/ml respectively for S. cannabina.

  11. The Crown Bite Jumping Herbst.

    PubMed

    Owen, Reuel

    2003-01-01

    The Crown Bite Jumping Herbst Appliance is evaluated and combined with Straight Wire Arch Fixed Orthodontics in treatment of Class II, Division I malocclusions. This article will evaluate a combined orthodontic approach of "straightening teeth" and an orthognathic approach of "moving jaws or making skeletal changes." Orthodontic treatment cannot be accomplished well without establishing a healthy temporomandibular joint. This is defined by Keller as a joint that is "noiseless, painless and has a normal range of motion without deviation and deflection." It is not prudent to separate orthodontic treatment as its own entity without being aware of the changes in the temporomandibular joint before, during and after treatment. In other words, "If you're doing orthodontics you're doing TMJ treatment." One should treat toward a healthy, beautiful face asking, "Will proposed treatment achieve this goal?" Treatment should be able to be carried out in an efficient manner, minimizing treatment time, be comfortable and affordable for the patient, and profitable for the dentist. The finished treatment should meet Andrews' Six Keys of Occlusion, or Loudon's Twelve Commandments. Above all, do no harm to the patient. We think that a specific treatment plan can embrace these tenets. The focus will be to show Class II treatment using a modified Herbst Appliance and fixed straight wire orthodontics.

  12. Oblique Corpectomy to Manage Cervical Myeloradiculopathy

    PubMed Central

    Salvatore, Chibbaro; Orphee, Makiese; Damien, Bresson; Alisha, Reiss; Pavel, Poczos; Bernard, George

    2011-01-01

    Background. The authors describe a lateral approach to the cervical spine for the management of spondylotic myeloradiculopathy. The rationale for this approach and surgical technique are discussed, as well as the advantages, disadvantages, complications, and pitfalls based on the author's experience over the last two decades. Methods. Spondylotic myelo-radiculopathy may be treated via a lateral approach to the cervical spine when there is predominant anterior compression associated with either spine straightening or kyphosis, but without vertebral instability. Results. By using a lateral approach, the lateral aspect of the cervical spine and the vertebral artery are easily reached and visualized. Furthermore, the lateral part of the affected intervertebral disc(s), uncovertebral joint(s), vertebral body(ies), and posterior longitudinal ligament can be removed as needed to decompress nerve root(s) and/or the spinal cord. Conclusion. Multilevel cervical oblique corpectomy and/or lateral foraminotomy allow wide decompression of nervous structures, while maintaining optimal stability and physiological motion of the cervical spine. PMID:22028964

  13. Borrelia burgdorferi tissue morphologies and imaging methodologies.

    PubMed

    MacDonald, A B

    2013-08-01

    This manuscript offers an image presentation of diverse forms of Borrelia burgdorferi spirochetes which are not spiral or corkscrew shaped. Explanations are offered to justify the legitimacy of tissue forms of Borrelia which may confuse the inexperienced microscopic examiner and which may lead to the misdiagnosis of non-spiral forms as artifacts. Images from the author's personal collection of Borrelia burgdorferi images and a few select images of Borrelia burgdorferi from the peer-reviewed published literature are presented. A commentary justifying each of the image profiles and a survey of the imaging modalities utilized provides the reader with a frame of reference. Regularly spiraled Borrelia are rarely seen in solid tissues. A variety of straightened, undulating, and clipped-off profiles are demonstrated, and the structural basis for each image is explained. Tissue examination is a diagnostic tool and a quality control for judging the eradication or the persistence of borreliosis following attempts to eradicate the infection with antibiotic therapy. The presence or absence of chronic Lyme borreliosis may be objectively adjudicated by tissue examinations which demonstrate or which fail to show pathogenic microbes in patients who have received a full course of antibiotics.

  14. The application of polymethylene waxes as conditioning agent in hair relaxers.

    PubMed

    Vermeulen, Shani; Van Rensburg, Audrey Jansen; Van Der Merwe, Belinda; Shalvoy, Richard; Willford, Suzanne

    2004-01-01

    Hair relaxers are harsh chemical treatments that leave the hair dull, dry and limp. There is a constant need for improvement of these products to make them milder and incorporate conditioning properties. Because of the high pH of relaxer or hair straightening systems, most quaternized (conditioning) ingredients are unstable and slowly break down to release ammonia over time, having no conditioning effects by the time the consumers use them. This paper discusses the partial substitution of the fatty alcohols that are traditionally used in relaxer systems with polymethylene wax and the benefits derived from using them. The study included the investigation of synergies among the ingredients, the stabilities of the various systems and comparisons with commercially available systems. The polymethylene wax, used in combination with the mineral oil gel and phosphate salt, coats the hair during the relaxing process, leaving it shiny, soft and conditioned as opposed to the poor condition of the hair relaxed by traditional, commercially available NaOH and LiOH relaxers. An additional benefit of using polymethylene wax in relaxer systems is that the conditioning agents that are normally added to the neutralizing shampoo to repair or mask the damage as a result of the relaxing process can be omitted.

  15. Chemical hair relaxers have adverse effects a myth or reality.

    PubMed

    Shetty, Vinma H; Shetty, Narendra J; Nair, Dhanya Gopinath

    2013-01-01

    Hair plays an important role in one's personality and builds confidence. Now-a-days, chemical hair relaxers are used very commonly in the society. We document the adverse effects reported by the sample that have used any one of the professional chemical hair relaxers. To study the adverse effects reported by the sample who underwent repeated chemical hair relaxing. Cross-sectional questionnaire based study done on a sample taken from a medical college and hospital campus in Mangalore. The sample was restricted to females and to those who underwent it more than once. A questionnaire was given to a sample of 90, which matched our criteria. SPSS software 17. Adverse effects reported by the sample after undergoing the procedure were found to be a high 95.56%, out of which the following are the common adverse effects reported; frizzy hair in 67%, dandruff in 61%, hair loss in 47%, thinning and weakening of hair in 40%, greying of hair 22%, and split ends in only 17%. Very few studies have been conducted on the adverse effects of hair straightening products in India. From our study, it can be stated that most of the samples had adverse effects, which was as high as 95.56%. Hence from the details elicited from this study, we can conclude that, usage of chemical hair relaxers does cause adverse effects and is "not a myth." Thus, it is necessary to make available a less harmful chemical hair relaxer to the society.

  16. The efficacy and safety of subcision using CO2 gas combined with fractional laser for acne scars: Clinical and microscopic evaluation.

    PubMed

    Lee, Sang Jun; Suh, Dong Hye; Chang, Ka Yeon; Kim, Hyun Joo; Kim, Tae In; Jeong, Ki-Heon; Shin, Min Kyung; Song, Kye Yong

    2016-11-01

    Various modalities have been used to treat acne scars. CO2 fractional laser is an effective and commonly used treatment. CO2 gas injection into the dermis by needle with high pressure can cause fibrotic collagen breakage, producing the effects of subcision. CO2 also stimulates collagen synthesis by increasing neovascularization and releasing oxygen. This study evaluated the efficacy and the safety of the combined treatment with CO2 gas subcision and CO2 fractional laser for acne scars. Fourteen patients with acne scars were treated with three sessions of CO2 gas subcision at 2-week intervals and two sessions of fractional laser at 4-week interval. The clinical improvement was assessed using a 4-point scale. For histologic analysis, punch biopsy was performed before and after treatment in 10 patients. All patients experienced clinical improvements. Excellent, marked, moderate, and mild response was achieved in 1 (7%), 8 (57%), 4 (29%), and 1 patient (7%), respectively. Histologic evaluation of the biopsy specimens showed increased dermal collagen with dermal thickening and elastic fiber straightening in the reticular dermis after the treatment. The combination therapy with CO2 gas subcision and fractional laser was satisfactory and safe for treating acne scars. Abbreviation and acronym: CO2: Carbon dioxide GAS: Global assessment scale H&E: hematoxylin and eosin; SD: standard deviation.

  17. An Excel™-VBA programme for the analysis of current velocity profiles

    NASA Astrophysics Data System (ADS)

    Le Roux, J. P.; Brodalka, M.

    2004-10-01

    VPA is an Excel spreadsheet to facilitate the analysis of current velocity profiles and its application to sediment transport studies in steady, uniform, open-channel flows. The program requires input values such as the water temperature (from which the density and dynamic viscosity are calculated), the channel depth and slope, current velocities as measured at different heights above the bed, bedform length and height, as well as the sediment density and median size. The latter can be provided as sieve diameters, fall diameters or as phi values. The velocity profiles are plotted on two graphs, one being a traditional plot of velocity versus height or distance from the bed and the other comparing the observed profile with theoretical profiles for smooth, transitional and rough boundary conditions. VBA macros are provided to clear the spreadsheet before new profiles are analysed, update the formulas, straighten out the velocity profiles, calculate the shear velocity, and save the data on a separate sheet for further analysis. The programme is applied to a new and more accurate method to determine the shear velocity, which can be used to predict the bedload discharge over plane beds and is also incorporated into a dimensionally correct suspended load transport equation combining the parameters most important in sediment transport. A dimensionally correct bedload discharge equation based upon the mean excess flow velocity is also proposed for plane beds, ripples and dunes.

  18. [Forensic aspects of thermal changes in human head hair].

    PubMed

    Kijewski, Harald

    2014-01-01

    Under experimental conditions, head hairs of individuals of different age were exposed to defined increases of temperature up to 450 degrees C and examined by transmitted- and reflected-light microscopy with and without polarization. Preliminary tests had shown that the hair changes alone do not allow conclusions as to the temperature acting on the hair. Especially in the range of 200 to 300 degrees C, the temperature gradient during the heating process and the exposure time were additional influencing factors. Thick hair and hair with a high water content showed more pronounced thermal changes than thin hair. Elasticity and permeability of the cuticle and the cementing substance (cell membrane complex CMC) are also relevant factors. When heating head hairs lacking a medulla, a multiform pseudo-medulla formed under certain conditions. In the presence of thermally induced structural disturbances (e.g. by using hair straighteners), foreign substances can penetrate more easily into the hair shaft from outside. The possibility of such exogenous contamination has to be taken into consideration when performing chemical and toxicological analyses of hair.

  19. Enhanced ectodysplasin-A receptor (EDAR) signaling alters multiple fiber characteristics to produce the East Asian hair form.

    PubMed

    Mou, Chunyan; Thomason, Helen A; Willan, Pamela M; Clowes, Christopher; Harris, W Edwin; Drew, Caroline F; Dixon, Jill; Dixon, Michael J; Headon, Denis J

    2008-12-01

    Hair morphology differs dramatically between human populations: people of East Asian ancestry typically have a coarse hair texture, with individual fibers being straight, of large diameter, and cylindrical when compared to hair of European or African origin. Ectodysplasin-A receptor (EDAR) is a cell surface receptor of the tumor necrosis factor receptor (TNFR) family involved in the development of hair follicles, teeth, and sweat glands. Analyses of genome-wide polymorphism data from multiple human populations suggest that EDAR experienced strong positive selection in East Asians. It is likely that a nonsynonymous SNP in EDAR, rs3827760, was the direct target of selection as the derived p.Val370Ala variant is seen at high frequencies in populations of East Asian and Native American origin but is essentially absent from European and African populations. Here we demonstrate that the derived EDAR370A common in East Asia has a more potent signaling output than the ancestral EDAR370 V in vitro. We show that elevation of Edar activity in transgenic mice converts their hair phenotype to the typical East Asian morphology. The coat texture becomes coarse, with straightening and thickening of individual hairs and conversion of fiber cross-sectional profile to a circular form. These thick hair fibers are produced by enlarged hair follicles, which in turn develop from enlarged embryonic organ primordia. This work shows that the multiple differences in hair form between East Asian and other human populations can be explained by the simplest of genetic alterations.

  20. Dynamic tricuspid valve stenosis induced with a pacemaker lead: a case report.

    PubMed

    Skoric, Bosko; Baricevic, Zeljko; Brida, Margarita; Samardzic, Jure; Jurin, Hrvoje; Milicic, Davor

    2014-01-01

    Isolated severe tricuspid valve stenosis due to an endocardial pacemaker lead is extremely rare, and is usually caused by either fibrosis of a perforated or lacerated leaflet, or fibrotic adherence between the lead and the valvular apparatus. Reported cases typically include clinical manifestations of both systemic venous stasis and low cardiac output. The case is presented of a 20-year-old female with a surgically repaired congenital heart disease who developed severe tricuspid stenosis at six years after the implantation of a DDD pacemaker. Unexpectedly, the patient had no signs of venous stasis and suffered only from exercise intolerance. Right heart catheterization under fluoroscopic guidance revealed an atrial lead forming a loop at the level of the tricuspid valve. A paradoxical inspiratory decrease in the transvalvular diastolic gradient, caused by the caudal heart motion and straightening of the loop during inspiration, was noted. Such a dynamic nature with a temporary inspiratory relief of the obstruction may explain the partial clinical presentation of tricuspid stenosis in this case. The lead was removed and the tricuspid valve repaired surgically, after which the patient's recovery was uneventful with normalization of exercise tolerance.

  1. Collection and collation: theory and practice of Linnaean botany.

    PubMed

    Müller-Wille, Staffan

    2007-09-01

    Historians and philosophers of science have interpreted the taxonomic theory of Carl Linnaeus (1707-1778) as an 'essentialist', 'Aristotelian', or even 'scholastic' one. This interpretation is flatly contradicted by what Linnaeus himself had to say about taxonomy in Systema naturae (1735), Fundamenta botanica (1736) and Genera plantarum (1737). This paper straightens out some of the more basic misinterpretations by showing that: (1) Linnaeus's species concept took account of reproductive relations among organisms and was therefore not metaphysical, but biological; (2) Linnaeus did not favour classification by logical division, but criticized it for necessarily failing to represent what he called 'natural' genera; (3) Linnaeus's definitions of 'natural' genera and species were not essentialist, but descriptive and polytypic; (4) Linnaeus's method in establishing 'natural' definitions was not deductive, but consisted in an inductive, bottom-up procedure of comparing concrete specimens. The conclusion will discuss the fragmentary and provisional nature of Linnaeus's 'natural method'. I will argue in particular that Linnaeus opted for inductive strategies not on abstract epistemological grounds, but in order to confer stability and continuity to the explorative practices of contemporary natural history.

  2. Oscillatory shear loading of bovine periodontal ligament--a methodological study.

    PubMed

    Sanctuary, Colin S; Wiskott, H W Anselm; Botsis, John; Scherrer, Susanne S; Belser, Urs C

    2006-06-01

    This study examined the stress response of bovine periodontal ligament (PDL) under sinusoidal straining. The principle of the test consisted in subjecting transverse tooth, PDL and bone sections of known geometries to controlled oscillatory force application. The samples were secured to the actuator by support plates fabricated using a laser sintering technique to fit their contours to the tooth and the alveolar bone. The actuator was attached to the root slices located in the specimen's center. Hence the machine was able to push or pull the root relative to its surrounding alveolar bone. After determining an optimal distraction amplitude, the samples were cyclically loaded first in ramps and then in sinusoidal oscillations at frequencies ranging from 0.2 to 5 Hz. In the present study the following observations were made: (1) Imaging and the laser sintering technique can be used successfully to fabricate custom-made support plates for cross-sectional root-PDL-bone sections using a laser sintering technique, (2) the load-response curves were symmetric in the apical and the coronal directions, (3) both the stress response versus phase angle and the stress response versus. strain curves tended to "straighten" with increasing frequency, and (4) the phase lag between applied strain and resulting stress was small and did not differ in the intrusive and the extrusive directions. As no mechanical or time-dependent anisotropy was demonstrable in the intrusive and extrusive directions, such results may considerably simplify the development of constitutive laws for the PDL.

  3. [Plain radiographs of the spine: static and relationships between spine and pelvis].

    PubMed

    Morvan, G; Wybier, M; Mathieu, P; Vuillemin, V; Guerini, H

    2008-05-01

    Man, with his erect posture, evolves in a world subject to the laws of gravity. His spine reflects these constraints. The morphology and static of human spine and biomechanical relationships between spine and pelvis are in direct relation with bipedia. Owing to this position the pelvis widened and straightened, characteristic sagittal spinal curves appeared and the perispinal muscles were deeply reorganized. Each pelvis is characterized by an important anatomical landmark: the pelvic incidence that reflects the sagittal morphology of the pelvis. Based on this anatomical characteristic, a chain of reactions determines the more efficient equilibrium of the whole body in the sagittal plane in term of energy consumption. Incidence affects the sacral slope, which determines lumbar lordosis, which itself influences pelvic tilt, thoracic kyphosis, and even hip and knee position. All these landmarks can easily be studied on a sagittal radiograph. Knowledge of these functional relationships is essential to understand the origin of low back pain, sagittal imbalance and above all before surgical treatment of spine disorders especially when arthrodesis is considered.

  4. Anthropometric changes and fluid shifts

    NASA Technical Reports Server (NTRS)

    Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

    1974-01-01

    Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

  5. Effect of a prior stretch on the aging response of an Al-Cu-Li-Ag-Mg-Zr alloy

    NASA Technical Reports Server (NTRS)

    Kumar, K. S.; Brown, S. A.; Pickens, Joseph R.

    1991-01-01

    Recently, a family of Al-Cu-Li alloys containing minor amounts of Ag, Mg, and Zr and having desirable combinations of strength and toughness were developed. The Weldalite (trademark) alloys exhibit a unique characteristic in that with or without a prior stretch, they obtain significant strength-ductility combinations upon natural and artificial aging. The ultra-high strength (approximately 690 MPa yield strength) in the peak-aged tempers (T6 and T8) were primarily attributed to the extremely fine T(sub 1) (Al2CuLi) or T(sub 1)-type precipitates that occur in these alloys during artificial aging, whereas the significant natural aging response observed is attributed to strengthening from delta prime (Al3Li) and GP zones. In recent work, the aging behavior of an Al-Cu-Li-Ag-Mg alloy without a prior stretch was followed microstructurally from the T4 to the T6 condition. Commercial extrusions, rolled plates, and sheets of Al-Cu-Li alloys are typically subjected to a stretching operation before artificial aging to straighten the extrusions and, more importantly, introduce dislocations to simulate precipitation of strengthening phases such as T(sub 1) by providing relatively low-energy nucleation sites. The goals of this study are to examine the microstructure that evolves during aging of an alloy that was stretch after solution treatment and to compare the observations with those for the unstretched alloy.

  6. RNA-d2: a computer program for editing and display of RNA secondary structures.

    PubMed

    Perochon-Dorisse, J; Chetouani, F; Aurel, S; Iscolo, N; Michot, B

    1995-02-01

    RNA-d2 is a user-friendly program developed for interactively generating aesthetic and non-overlapping drawings of RNA secondary structures. It designed so that the drawings can be edited in a very natural and intuitive way, in order to emphasize structural homologies between several molecules, as well as the foldings themselves to update the base-pair sets according to new data. The program automatically produces a polygonal display in which the unpaired nucleotides are regularly positioned on circles and the stems harmoniously distributed on their periphery. RNA secondary structures can be encoded via the keyboard, but the program also automatically draws output files from thermodynamic prediction programs. The user interacts directly on different screen displays according to the editing functions. Rotation/translation of any subdomain and deletion of stems are performed on a coloured backbone view to make easier the identification of structural features, whereas addition of new base-pairings and numbering manipulation are realized on a complete polygonal view. Each modification is displayed in real time on the screen. When the display is obscured by numerous overlaps despite the colour code of the backbone view, an automatic function progressively straightens the subdomains which are highly compacted by very dissymmetric internal loops. RNA-d2 allows easy untangling and editing of RNA molecules > 1000 nucleotides long.

  7. Impact of Endometrioma Resection on Eutopic Endometrium Metabolite Contents: Noninvasive Evaluation of Endometrium Receptivity.

    PubMed

    Ersahin, Aynur; Celik, Onder; Acet, Mustafa; Ersahin, Suphan; Acet, Tuba; Kara Bozkurt, Duygu; Yavuz, Yasemin; Ilhan, Selcuk

    2016-09-27

    The aim of this study was to determine whether endometrioma resection alters most commonly defined endometrial metabolites, lactate (Lac), N-acetylaspartate (NAA), creatine 1 (Cr1), creatine 2 (Cr2), and choline (Cho) during the window of implantation. Twenty patients with uni- or bilateral endometrioma and 7 patients having nonendometriotic benign ovarian cyst were included. Midluteal phase magnetic resonance spectroscopy analysis of eutopic endometrium was performed before surgery. Second spectrum of endometrium was obtained 3 to 5 months after laparoscopic endometrioma resection. Pre- and postoperative endometrial peaks of Lac, NAA, Cr, and Cho were measured in units and denominated in parts per million (ppm). Compared to preoperative peak values, significantly decreased NAA, Lac, and Cr1 signals were noted in patients undergoing endometrioma surgery. Nearly 5-fold decline in the NAA signal occurred after endometrioma surgery (1.94 ± 3.24 vs 0.37 ± 0.55). Likewise, 2.5-fold decline in Lac signals was noted after endometrioma resection (2.81 ± 2.64 vs 1.06 ± 1.88). Both uni- and bilateral endometrioma affected endometrium signals the same. The peak intensity of Cho, Cr1, Cr2, NAA, and Lac did not alter significantly after nonendometriotic cyst surgery. Endometrioma surgery straightens endometrial NAA, Lac, and Cr1 peaks, suggesting improvement in endometrial receptivity.

  8. Determination of pre-impact occupant postures and analysis of consequences on injury outcome. Part I: a driving simulator study.

    PubMed

    Hault-Dubrulle, Audrey; Robache, Frederic; Pacaux, Marie-Pierre; Morvan, Herve

    2011-01-01

    This paper considers pre-impact vehicle maneuvers and analyzes the resulting driver motion from their comfort seating position. Part I of this work consists of analyzing the driver behavior during a crash. The study is conducted using the LAMIH driving simulator and involves 76 participants. The emergency situation is created by a truck emerging from behind a tractor on the opposite side of the road and tearing along the participant. The driver positioning throughout the simulation is recorded via five video cameras allowing view of the front scene, the driver face, feet and pedals, hands on the steering wheel and global lateral view. Data related to braking force, seat pressure, muscular activity for major groups of muscles and actions on the steering wheel are also collected. The typical response to this type of emergency event is to brace rearward into the seat and to straighten the arms against the steering wheel, or, to swerve to attempt to avoid the impacting vehicle. While turning the steering wheel, the forearm can be directly positioned on the airbag module at time of crash which represents a potential injurious situation. These positions are used in Part II to determine scenario of positions for numerical simulation of a frontal collision. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Conducting nanowires in insulating ceramics.

    PubMed

    Nakamura, Atsutomo; Matsunaga, Katsuyuki; Tohma, Jun; Yamamoto, Takahisa; Ikuhara, Yuichi

    2003-07-01

    Low-dimensional structures, such as microclusters, quantum dots and one- or two-dimensional (1D or 2D) quantum wires, are of scientific and technological interest due to their unusual physical properties, which are quite different from those in the bulk. Here we present a successful method for fabricating conducting nanowire bundles inside an insulating ceramic single crystal by using unidirectional dislocations. A high density of dislocations (10(9) cm(-2)) was introduced by activating a primary slip system in sapphire (alpha-Al2O3 single crystal) using a two-stage deformation technique. Plate specimens cut out from the deformed sapphire were then annealed to straighten the dislocations. Finally, the plates on which metallic Ti was evaporated were heat-treated to diffuse Ti atoms inside sapphire. As a result of this process, Ti atoms segregated along the unidirectional dislocations within about 5 nm diameter, forming unidirectional Ti-enriched nanowires, which exhibit excellent electrical conductivity. This simple technique could potentially to be applied to any crystal, and may give special properties to commonly used materials.

  10. Semi-automated nanoprecipitation-system--an option for operator independent, scalable and size adjustable nanoparticle synthesis.

    PubMed

    Rietscher, René; Thum, Carolin; Lehr, Claus-Michael; Schneider, Marc

    2015-06-01

    The preparation of nano-sized carrier systems increasingly moved into focus of pharmaceutical research and industry in the past decades. Besides the drug load and properties of the selected polymer/lipid, the size of such particles is one of the most important parameters regarding their use as efficient drug delivery systems. However, the preparation of nanoparticles with different sizes in a controlled manner is challenging, especially in terms of reproducibility and scale-up possibility. To overcome these hurdles we developed a system relying on nanoprecipitation, which meets all these requirements of an operator independent, scalable and size-adjustable nanoparticle synthesis-the Semi-Automated Nanoprecipitation-System. This system enables the adaption of the particle size to specific needs based on the process parameters-injection rate, flow rate and polymer concentration-identified within this study. The basic set-up is composed of a syringe pump and a gear pump for a precise control of the flow and injection speed of the system. Furthermore, a home-made tube-straightener guarantees a curvature-free injection point. Thus it could be shown that the production of poly(lactide-co-glycolide) nanoparticles from 150 to 600 nm with a narrow size distribution in a controlled semi-automatic manner is possible.

  11. A geometric model of plaque incision and graft for Peyronie's disease with geometric analyses of different techniques.

    PubMed

    Miranda, Alexandre F; Sampaio, Francisco J B

    2014-06-01

    A surgical approach with plaque incision and graft (PIG) to correct Peyronie's disease is the best method for complex, large deviations. However, the geometric and mechanical consequences of this intervention are poorly understood. The aim of this study was to analyze the geometric and mechanical consequences of PIG on penile straighten surgery. A tridimensional penile simile model with a curvature of 85° was created to test all of the most common PIG techniques. PIG with double-Y, H-shape, and Egydio techniques were used to rectify the curved penile model. The results that differed from a rectified cylinder shape were highlighted. All of the analyzed techniques created a geometric distortion that could be linked to poor surgical results. We suggest a new technique to resolve these abnormalities. Current techniques designed to correct penile deviation using PIG present geometric and mechanical imperfections with potential consequences to the postoperative success rate. The new technique proposed in this report could be a possible solution to solve the geometric distortion caused by PIG. © 2014 International Society for Sexual Medicine.

  12. Analysis of the cranio-cervical curvatures in subjects with migraine with and without neck pain.

    PubMed

    Ferracini, Gabriela Natália; Chaves, Thais Cristina; Dach, Fabíola; Bevilaqua-Grossi, Débora; Fernández-de-Las-Peñas, César; Speciali, José Geraldo

    2017-03-24

    To investigate the differences in head and cervical spine alignment between subjects with migraine and healthy people. A cross-sectional, observational study. Fifty subjects with migraine and 50 matched healthy controls. The presence of neck pain and neck pain-related disability was assessed. Four angles (high cervical angle, low cervical angle, atlas plane angle and cervical lordosis Cobb angle) as well as four distances (anterior translation distance, C0 to C1 distance, C2 to C7 posterior translation and hyoid triangle) were calculated using digitalised radiographs and analysed using K-Pacs(®) software. Subjects with migraine reported a longer history of neck pain symptoms, and higher pain intensity and neck-pain-related disability than controls (P<0.01). Patients exhibited a smaller anterior translation distance (mean difference: 4.9mm, 95% confidence interval 1.8 to 8.8; P<0.001) and hyoid triangle (difference: 3.0mm, 95% confidence interval 1.0 to 5.0; P=0.02) than healthy controls. When the presence or the absence of neck pain was included in the analysis, the differences did not change. Differences in anterior translation and hyoid triangle distances were considered clinically relevant for subjects with migraine suffering from neck pain. Subjects with migraine exhibited straightening of cervical lordosis curvature. The presence of neck pain did not influence head posture in subjects with and without migraine. Copyright © 2017 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  13. A study of the microstructure of a rapidly solidified nickel-base superalloy modified with boron. M.S. Thesis. Final Contractor Report

    NASA Technical Reports Server (NTRS)

    Speck, J. S.

    1986-01-01

    The microstructures of melt-spun superalloy ribbons with variable boron levels have been studied by transmission electron microscopy. The base alloy was of approximate composition Ni-11% Cr-5%Mo-5%Al-4%Ti with boron levels of 0.06, 0.12, and 0.60 percent (all by weight). Thirty micron thick ribbons display an equiaxed chill zone near the wheel contact side which develops into primary dendrite arms in the ribbon center. Secondary dendrite arms are observed near the ribbon free surface. In the higher boron bearing alloys, boride precipitates are observed along grain boundaries. A concerted effort has been made to elucidate true grain shapes by the use of bright field/dark field microscopy. In the low boron alloy, grain shapes are often convex, and grain faces are flat. Boundary faces frequently have large curvature, and grain shapes form concave polygons in the higher boron level alloys. It is proposed that just after solidification, in all of the alloys studied, grain shapes were initially concave and boundaries were wavy. Boundary straightening is presumed to occur on cooling in the low boron alloy. Boundary migration is precluded in the higher boron alloys by fast precipitation of borides at internal interfaces.

  14. Geomorphological and seismological investigations in a part of western Kumaun Himalaya, Uttarakhand, India

    NASA Astrophysics Data System (ADS)

    Pathak, Vivekanand; Pant, Charu C.; Darmwal, Gopal Singh

    2013-07-01

    The Kumaun Himalaya in India is seismotectonically one of the most responsive sectors of the Himalayan arc. The region falls in the seismic gap and is frequently rocked by the earthquakes of low to medium magnitude. In the present investigation, the seismic data of the area were obtained by deploying a seismic network, and an attempt is made to interpret the seismological data of the local events and their relation with the geomorphology and thrusts/faults rejuvenation. The epicentral distribution of the earthquakes defines a relatively narrow zone of seismicity. A majority of earthquakes are confined to shallow depth with low stress drop and higher peak ground velocity (PGV). Further, the neotectonic investigations along the major river valleys indicate the neotectonic activity in the form of paired and unpaired terraces, shifting of river courses, fault scarps, development of palaeolakes, straightening of river channels, and deep cut V-shaped valleys. From the geomorphological and seismological data, the thrust and fault systems in the area are seismotectonically quite active even today. Some of the transverse faults — viz. Dwarahat-Chaukhutia fault, Takula-Basauli fault (Sim Gad valley), Tilora-Jyala fault (Kosi valley) — show spectacular tectonic landforms and seismicity. As a matter of fact, the NNW/NW-SSE/SE trending faults are active in the region.

  15. The effect of a flexed elbow on bowling speed in cricket.

    PubMed

    Marshall, Robert; Ferdinands, René

    2003-01-01

    The laws of bowling in cricket state 'a ball is fairly delivered in respect of the arm if, once the bowler's arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand'. Recently two prominent bowlers, under suspicion for transgressing this law, suggested that they are not 'throwing' but due to an elbow deformity are forced to bowl with a bent bowling arm. This study examined whether such bowlers can produce an additional contribution to wrist/ball release speed by internal rotation of the upper arm. The kinematics of a bowling arm were calculated using a simple two-link model (upper arm and forearm). Using reported internal rotation speeds of the upper arm from baseball and waterpolo, and bowling arm kinematics from cricket, the change in wrist speed was calculated as a function of effective arm length, and wrist distance from the internal rotation axis. A significant increase in wrist speed was noted. This suggests that bowlers who can maintain a fixed elbow flexion during delivery can produce distinctly greater wrist/ball speeds by using upper arm internal rotation.

  16. Penile prosthesis implantation and tunica albuginea incision without grafting in the treatment of Peyronie's disease with erectile dysfunction.

    PubMed

    Djordjevic, Miroslav L; Kojovic, Vladimir

    2013-05-01

    We evaluated penile prosthesis implantation with tunica albuginea-relaxing incisions without grafting in the treatment of Peyronie's disease associated with erectile dysfunction. Between April 2005 and June 2011, 62 patients underwent surgery due to severe Peyronie's disease associated with erectile dysfunction. Malleable and inflatable penile prostheses were inserted in 49 and 13 cases, respectively. Penile prostheses were inserted into the corpora cavernosa using the standard ventral approach. After lifting the neurovascular bundle, the tunica albuginea was incised and opened at the plaque region to correct the deformities and to lengthen the penis. Subsequently, the wide neurovascular bundle was replaced, and all incisions of the tunica albuginea were covered to prevent corporal grafting. In the median follow-up of 35 months (range 14-82 months), the penis was completely straightened in 59 (95%) patients. Numbness of the glans, which the patients found initially upsetting, decreased or disappeared spontaneously 3-6 months later. Penile prosthesis implantation with tunica albuginea incisions is a viable alternative in the treatment of Peyronie's disease because the extensive dissection of the neurovascular bundle allows a good approach to the plaque and provides excellent covering of the incised tunica albuginea without additional grafting.

  17. Target detection from MPEG video based on low-rank filtering in the compressed domain

    NASA Astrophysics Data System (ADS)

    Viangteeravat, Teeradache; Krootjohn, Soradech; Wilkes, D. M.

    2010-04-01

    There are advantages of using the motion vector obtained from the MPEG video coding to perform target of interest identification in the field. In practice, however, environment noise, time-varying, and uncertainty factors affect their performance reliably and accurately detecting targets of interest. In this paper, we proposed a novel low rank filtering based on L1 norm in order to straighten up single rogue or outliers that might show up fairly often. Finally, a simple average smoothing filter was applied to reduce vector quantization noise. By using the low rank filtering based on L1 norm, the dominant motion vectors from the MPEG video coding can be extracted appropriately with respect to target operational responses and can be used for robust identification of moving target. The performance of the proposed approach was evaluated based on a set of experimental camera motion. The motions, including pan, tilt, and zoom, was computed from the motion vectors, and the residual vectors which are not described by the camera motion are regarded as generated by moving blobs. Events, as a result, can be detected from these moving blobs. It is demonstrated that the approach yields very promising results where motion vectors obtained from the MPEG video coding can be used efficiently to detect and identify moving target in the field.

  18. Wave-particle dynamics of waveform and defect evolutions in undulated nonlinear self-excited dust acoustic waves

    SciTech Connect

    Tsai, Jun-Yi; Tsai, Ya-Yi; I, Lin

    2015-01-15

    The wave-particle dynamics for the evolutions of defects and surrounding pitchfork type waveforms of a weakly disordered self-excited dust acoustic wave is experimentally investigated in an rf dusty plasma system. Particle trajectories are tracked and correlated with waveform evolution to construct an Eulerian-Lagrangian wave-particle dynamical picture. It is found that the local accumulation and depletion of particles in the wave crest and rear, respectively, determines the local crest speed, and the growth and decay of the local crest height, which in turn determine the waveform evolution. The local crest height and the focusing and defocusing of particle trajectories due to the transverse force fields from the tilted wave crest and the non-uniform crest height along the wave crest are the key factors to determine the above particle accumulation and depletion. It explains the observations such as the lower speed of smaller crests, the straightening of the leading front of the pitchfork waveform associated with the transverse motion of defect to the open side, and the vertical defect gliding in the wave frame through the detachment of the strongly kinked pitchfork branch followed by its reconnection with the trailing crest.

  19. Designing a bio-inspired self-propelling hydrogel micro-swimmer

    NASA Astrophysics Data System (ADS)

    Nikolov, Svetoslav; Yeh, Peter; Alexeev, Alexander

    2014-11-01

    Artificial micro-swimmers have found numerous applications in microfluidics, drug delivery systems, and nanotechnology. In our current research we use dissipative particle dynamics to design and optimize a self-propelling hydrogel micro-swimmer with an X-shaped flat geometry and bi-layered hydrogel structure. The two polymeric layers that bind to each other have identical material properties but distinctive chemical responses to external stimuli. In the presence of outside stimuli one of the layers swells where the other remains passive resulting in hydrogel bending. Our simulations demonstrate that under periodic applications of an external stimulus this actuation routine is capable of creating time-irreversible motion in a low Reynolds number environment. Initially, when the external stimulus is introduced a forward stroke is initiated, as the swimmer first expands and then bends. When the outside stimulus is removed the forward stroke is terminated and a backward stroke begins, as the swimmer contracts and then straightens. Propulsion results due to the difference in momentum exchange between the forward and backward strokes. We use our simulations to probe how alterations in the material properties of the bi-layered hydrogel can affect swimming performance. Support from NSF CAREER Award (DMR-1255288) is gratefully acknowledged.

  20. The stress corrosion resistance and the cryogenic temperature mechanical properties of annealed Nitronic 60 bar material

    NASA Technical Reports Server (NTRS)

    Montano, J. W. L.

    1977-01-01

    Ambient and cryogenic temperature mechanical properties and the ambient temperature stress corrosion properties of annealed, straightened, and centerless ground Nitronic 60 stainless steel alloy bar material are presented. The mechanical properties of longitudinal specimens were evaluated at test temperatures from ambient to liquid hydrogen. The tensile test data indicated increasing strength with decreasing temperature to -196 C. Below liquid nitrogen temperature the smooth tensile and notched tensile strengths decreased slightly while the elongation and reduction of area decreased drastically. The Charpy V-notched impact energy decreased steadily with decreasing test temperature. Stress corrosion tests were performed on longitudinal tensile specimens and transverse C-ring specimens exposed to: alternate immersion in a 3.5% NaCl bath; humidity cabinet; and a 5% salt spray atmosphere. The longitudinal tensile specimens experienced no corrosive attack. Approximately 3/4 of the transverse C-rings exposed to alternate immersion and to salt spray experienced a pitting attack on the top and bottom ends. Additional stress corrosion tests were performed on transverse tensile specimens. No failures occurred in the 90% stressed specimens exposed for 90 days in the alternate immersion and salt spray environments

  1. The Suckling Hills Fault, Kayak Island Zone, and accretion of the Yakutat microplate, Alaska

    NASA Astrophysics Data System (ADS)

    Chapman, James B.; Worthington, Lindsay L.; Pavlis, Terry L.; Bruhn, Ronald L.; Gulick, Sean P.

    2011-12-01

    The Suckling Hills and Kayak Island are isolated mountain blocks located along strike from each other within the foreland of the St. Elias orogen in southern Alaska. These blocks preserve an erosional surface that was deformed by slip on northwest-dipping reverse faults in the Pleistocene. We suggest that the Suckling Hills Fault and Kayak Island Zone form a segmented fault network that links with the Bering Glacier structure to the north. This fault network separates the central Yakataga fold and thrust belt from complex, multiply deformed structures in the western syntaxis. Ongoing accretion of the Yakutat microplate to North America results in translation of structures of the fold and thrust belt into the western syntaxis. The composite Suckling Hills Fault, Kayak Island Zone, and Bering Glacier structure may have formed because the older structures of the fold and thrust belt were unfavorably oriented within the western syntaxis region. This pattern of deformation provides a template for understanding the complex deformation within the core of the western syntaxis and predicts refolding and straightening of the western syntaxis margin with continued accretion. This study provides an analog for structural overprinting and changing deformation patterns through time in orogenic corners.

  2. Preparation of severely curved simulated root canals using engine-driven rotary and conventional hand instruments.

    PubMed

    Szep, S; Gerhardt, T; Leitzbach, C; Lüder, W; Heidemann, D

    2001-03-01

    This in vitro study evaluated the efficacy and safety of six different nickel-titanium engine-driven instruments used with a torque-controlled engine device and nickel-titanium hand and stainless steel hand instruments in preparation of curved canals. A total of 80 curved (36 degrees) simulated root canals were prepared. Images before and after were superimposed, and instrumentation areas were observed. Time of instrumentation, instrument failure, change in working length and weight loss were also recorded. Results show that stainless steel hand instruments cause significantly less transportation towards the inner wall of the canal than do nickel-titanium hand instruments. No instrument fracture occurred with hand instruments, but 30-60% breakage of instruments was recorded during instrumentation with the engine-driven devices. The working length was maintained by all types of instruments. Newly developed nickel-titanium rotary files were not able to prevent straightening of the severely curved canals when a torque-controlled engine-driven device was used.

  3. Myosin lever arm directs collective motion on cellular actin network

    PubMed Central

    Hariadi, Rizal F.; Cale, Mario; Sivaramakrishnan, Sivaraj

    2014-01-01

    The molecular motor myosin teams up to drive muscle contraction, membrane traffic, and cell division in biological cells. Myosin function in cells emerges from the interaction of multiple motors tethered to a scaffold, with surrounding actin filaments organized into 3D networks. Despite the importance of myosin function, the influence of intermotor interactions on collective motion remains poorly understood. In this study, we used precisely engineered myosin assemblies to examine emergence in collective myosin movement. We report that tethering multiple myosin VI motors, but not myosin V motors, modifies their movement trajectories on keratocyte actin networks. Single myosin V and VI dimers display similar skewed trajectories, albeit in opposite directions, when traversing the keratocyte actin network. In contrast, tethering myosin VI motors, but not myosin V motors, progressively straightens the trajectories with increasing myosin number. Trajectory shape of multimotor scaffolds positively correlates with the stiffness of the myosin lever arm. Swapping the flexible myosin VI lever arm for the relatively rigid myosin V lever increases trajectory skewness, and vice versa. A simplified model of coupled motor movement demonstrates that the differences in flexural rigidity of the two myosin lever arms is sufficient to account for the differences in observed behavior of groups of myosin V and VI motors. In accordance with this model trajectory, shapes for scaffolds containing both myosin V and VI are dominated by the myosin with a stiffer lever arm. Our findings suggest that structural features unique to each myosin type may confer selective advantages in cellular functions. PMID:24591646

  4. Ground reaction forces of Olympic and World Championship race walkers.

    PubMed

    Hanley, Brian; Bissas, Athanassios

    2016-01-01

    Race walking is an Olympic event where no visible loss of contact should occur and the knee must be straightened until midstance. The purpose of this study was to analyse ground reaction forces of world-class race walkers and associate them with key spatiotemporal variables. Nineteen athletes race walked along an indoor track and made contact with two force plates (1000 Hz) while being filmed using high-speed videography (100 Hz). Race walking speed was correlated with flight time (r = .46, p = .049) and flight distance (r = .69, p = .001). The knee's movement from hyperextension to flexion during late stance meant the vertical push-off force that followed midstance was smaller than the earlier loading peak (p < .001), resulting in a flattened profile. Athletes with narrower stride widths experienced reduced peak braking forces (r = .49, p = .046), peak propulsive forces (r = .54, p = .027), peak medial forces (r = .63, p = .007) and peak vertical push-off forces (r = .60, p = .011). Lower fluctuations in speed during stance were associated with higher stride frequencies (r = .69, p = .001), and highlighted the importance of avoiding too much braking in early stance. The flattened trajectory and consequential decrease in vertical propulsion might help the race walker avoid visible loss of contact (although non-visible flight times were useful in increasing stride length), while a narrow stride width was important in reducing peak forces in all three directions and could improve movement efficiency.

  5. Improved pulmonary nodule classification utilizing lung parenchyma texture features

    NASA Astrophysics Data System (ADS)

    Dilger, S. K.; Judisch, A.; Uthoff, J.; Hammond, E.; Newell, J. D.; Sieren, J. C.

    2015-03-01

    Current computer-aided diagnosis (CAD) models, developed to determine the malignancy of pulmonary nodules, characterize the nodule's shape, density, and border. Analyzing the lung parenchyma surrounding the nodule is an area that has been minimally explored. We hypothesize that improved classification of nodules can be achieved through the inclusion of features quantified from the surrounding lung tissue. From computed tomography (CT) data, feature extraction techniques were developed to quantify the parenchymal and nodule textures, including a three-dimensional application of Laws' Texture Energy Measures. Border irregularity was investigated using ray-casting and rubber-band straightening techniques, while histogram features characterized the densities of the nodule and parenchyma. The feature set was reduced by stepwise feature selection to a few independent features that best summarized the dataset. Using leave-one-out cross-validation, a neural network was used for classification. The CAD tool was applied to 50 nodules (22 malignant, 28 benign) from high-resolution CT scans. 47 features, including 39 parenchymal features, were statistically significant, with both nodule and parenchyma features selected for classification, yielding an area under the ROC curve (AUC) of 0.935. This was compared to classification solely based on the nodule yielding an AUC of 0.917. These preliminary results show an increase in performance when the surrounding parenchyma is included in analysis. While modest, the improvement and large number of significant parenchyma features supports our hypothesis that the parenchyma contains meaningful data that can assist in CAD development.

  6. Mechanisms of force and power production in unsteady ricochetal brachiation.

    PubMed

    Usherwood, James R; Larson, Susan G; Bertram, John E A

    2003-04-01

    Brachiators travel by swinging beneath handholds, and it is not obvious how these animals manage to accelerate and decelerate in a horizontal direction, especially when moving rapidly. Most previous analyses focused on brachiation in highly constrained laboratory conditions that induced steady-state locomotion. Emerging understanding of brachiation suggests that much of gibbon locomotory behavior and morphology must be considered within the context of the complexities of the natural environment: the forest canopy is three-dimensional, with high variation in handhold availability and properties. The goal of this paper is to quantify the active mechanisms by which gibbons can dynamically control their velocity. Force production and kinematics were analyzed from a white-handed gibbon Hylabates lar during ricochetal brachiation. Both the mechanisms of force production and power input may be inferred for accelerating and decelerating brachiation by combining force data with kinematics. Examples of steady-state, accelerating, and decelerating ricochetal brachiation are highlighted. Gibbons are able to produce net horizontal impulses by releasing early (resulting in a loss of potential energy, but an accelerating horizontal impulse) or delaying release (associated with an increase in potential energy, and a decelerating horizontal impulse). Torque about the shoulder, leg-lifting (or dropping), and elbow flexing (or straightening) are discussed as potential mechanisms for controlling energy within the brachiating system. Of these possibilities, leg-lifting and arm-flexing were observed as mechanisms of adding mechanical energy. Net energy loss, and substantial torques about the shoulder, were not observed. Copyright 2003 Wiley-Liss, Inc.

  7. Concurrent Angioplasty Balloon Placement for Stent Delivery through Jugular Venous Bulb for Treating Cerebral Venous Sinus Stenosis. Technical Report.

    PubMed

    Qureshi, Adnan I; Khan, Asif A; Capistrant, Rachel; Qureshi, Mushtaq H; Xie, Kevin; Suri, M Fareed K

    2016-10-01

    To report upon technique of concurrent placement of angioplasty balloon at the internal jugular vein and sigmoid venous sinus junction to facilitate stent delivery in two patients in whom stent delivery past the jugular bulb was not possible. A 21-year-old woman and a 41-year-old woman with worsening headaches, visual obscuration or diplopia were treated for pseudotumor cerebri associated with transverse venous stenosis. Both patients had undergone primary angioplasty, which resulted in improvement in clinical symptoms followed by the recurrence of symptoms with restenosis at the site of angioplasty. After multiple attempts at stent delivery through jugular venous bulb were unsuccessful, a second guide catheter was placed in the ipsilateral internal jugular vein through contralateral femoral venous approach. A 6 mm × 20 mm (left) or 5 × 15 mm (right) angioplasty balloon was placed across the internal jugular vein and sigmoid sinus junction and partially inflated until the inflation and relative straightening of the junction was observed. In both patients, the internal jugular vein and sigmoid sinus junction was successfully traversed by the stent delivery system in a parallel alignment to inflated balloon. Balloon mounted stent was deployed at the site of restenosis with near complete resolution of lumen narrowing delivery and improvement in clinical symptoms. We report a technique for realignment and diameter change with concurrent placement and partial inflation of angioplasty balloon at the jugular venous bulb to facilitate stent delivery into the sigmoid and transverse venous sinuses in circumstances where multiple attempts at stent delivery are unsuccessful.

  8. Peyronie curvature treated by plication of the penile fasciae.

    PubMed

    Geertsen, U A; Brok, K E; Andersen, B; Nielsen, H V

    1996-05-01

    To evaluate the results of plication of the penile fascia in patients with penile curvature secondary to Peyronie's disease. Twenty-eight men with Peyronie curvature underwent plication of the penile fascia. Before operation, the deviation of the penis was so severe (median 60 degrees) in 24 men that they were unable to perform sexual intercourse. Follow-up was based on hospital records, one postal questionnaire sent to all patients and a clinical evaluation of the men in the out-patient clinic. After an uncomplicated operation and a median follow-up of 34 months, 20 of the 28 men were able to perform sexual intercourse and 23 were satisfied with the result of the operation. The most frequent reasons for dissatisfaction with the outcome of the operation were insufficient straightening, pain from sutures and uncharacteristic pain related to the penis and/or scrotum. The technique is simple to perform and the method gives functional and cosmetic results equal to those of more invasive procedures. The provision of adequate information to patients before the operation is important to ensure their satisfaction with the outcome.

  9. Lingual mucosal graft in treatment of Peyronie disease.

    PubMed

    Salem, Emad A; Elkady, Ehab H; Sakr, Ahmed; Maarouf, Aref M; Bendary, Lotfy; Khalil, Salem; Shahin, Ashraf; Kamel, Hussein

    2014-12-01

    To evaluate the use of lingual mucosal graft (LMG) as a substitute for tunica albuginea in the treatment of Peyronie disease (PD). Seventeen patients, reporting normal erectile function, with PD interfering with sexual function were operated on by plaque excision and grafting with LMG. Preoperative assessment included: the International Index of Erectile Function-5 score, penile duplex, and penile curvature angle measurement. Postoperative erectile function and penile deformity were assessed every 3 months for 9-18 months. Mean age of the patients was 52 (± 4.7) years and mean angle of deformity was 60° (± 5.1). Donor site complications occurred in the form of mild transient swelling, numbness, and pain. Postoperative assessment showed complete penile straightening in 15 patients with mild curvature recurrence (<20°) in 2 patients at the third month. De novo mild erectile dysfunction was reported by 1 patient who responded to low-dose phosphodiesterase type 5 inhibitor. Patients' and partners' satisfaction was reported in 16 (94%) patients. These results remained stable until the end of the follow-up period. LMG seems to be a valuable substitute for tunica albuginea in cases of PD. It is readily available and shows early graft take. It also proved safety, reliability, feasibility, and a satisfactory short-term outcome for the treatment of PD. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Helical reconstruction of frozen-hydrated scallop myosin filaments.

    PubMed

    Vibert, P

    1992-02-05

    Native myosin filaments from scallop striated muscle that have been rapidly frozen in relaxing solutions appear to be well preserved in vitreous ice. Electron micrographs of samples at -177 degrees C were recorded with an electron dose of 10 e/A2 at 1.5 microns defocus. After filament images were straightened by spline-fitting, several transforms showed well-defined layer-lines arising from the helical structure of the filament. A set of 17 near-meridional layer-lines has been collected and corrected for background and for phase and amplitude contrast functions. Preliminary helical reconstructions from this still incomplete data set reveal aspects of structure that were not apparent from earlier analysis of negatively stained filaments from scallop muscle. Individual pear-shaped myosin heads now appear to be well resolved from each other and from the filament backbone. The two heads of each myosin molecule appear to be splayed apart axially. The reconstructions also reveal that the filament backbone has a polygonal shape in cross-section, and that it appears to contain seven peripherally located subfilaments.

  11. The influence of the lower beak on the interorbital septum-prenasal process complex in the chick embryo.

    PubMed

    Wouterlood, F G; van Pelt, W

    1979-01-01

    The effect of removal of the lower beak on the development of the interorbital septumprenasal process (ISPP) complex was studied in chick embryos. In normal development the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process increases. At the same time the angle between the ventral contour of the interorbital septum and the basal plate increases. After surgical removal of the prospective lower beak at stage 29, the position of the entire ISPP complex was altered in stage-38 embryos and the prenasal process showed elongation. In stage-38 embryos in which the prospective upper beak had been removed at stage 29, Meckel's cartilage was elongated. It is concluded that straightening of the angle between the ventral contour of the interorbital septum and the long axis of the prenasal process is not influenced by the lower beak, whereas the position of the entire ISPP complex and the size of the prenasal process are under the epigenetic influence of the lower beak. The position and size of Meckel's cartilage are under the epigenetic influence of the upper beak.

  12. Performance evaluation of panoramic electro-optic imagers using the TOD method

    NASA Astrophysics Data System (ADS)

    Désaulniers, Pierre; Thibault, Simon

    2011-05-01

    The triangle orientation discrimination (TOD) method is an emerging technique for the evaluation of electro-optical (EO) systems. In this method, the test pattern is a non-periodic equilateral triangle in one of four different orientations (apex up, down, left, or right), and the measurement procedure is a robust four-alternative forced-choice psychophysical process. This leads to a time-consuming task. Consequently, software models have been developed to replace the required human observers. These models base their decision on the orientation of the target using correlation between observed data and the set of four differently oriented targets. This study investigates for the first time how this method can be applied to highly distorted OE systems like hemispheric imagers. These types of systems have inherent large distortion, but the distortion should not be considered as an aberration but rather the result of the projection of a hemispheric field (3D) on a 2D sensor. The distortion deforms the image of the targets and image processing is usually performed to remove distortion and straighten the field of view. We present a comparison in accuracy and computational burden for the evaluation of EO system performance between cases where tested images are pre-processed and correlated to unchanged triangle targets and where untouched (distorted) images are correlated with position-wise distorted targets. This is a first evaluation of the application of the TOD with the goal of obtaining an image quality criterion for panoramic imagers.

  13. Optical and Calorimetric Studies of Cholesterol-Rich Filamentous, Helical Ribbon and Crystal Microstructures (abstract)

    NASA Astrophysics Data System (ADS)

    Miroshnikova, Y. A.; Elsenbeck, M.; Kashuri, K.; Iannacchione, G. S.; Zastavker, Y. V.

    2009-04-01

    Formation of biological self-assemblies at all scales is a focus of studies in fields ranging from biology to physics to biomimetics. Understanding the physico-chemical properties of these self-assemblies may lead to the design of bio-inspired structures and technological applications. Here we examine self-assembled filamentous, helical ribbon, and crystal microstructures formed in chemically defined lipid concentrate (CDLC), a model system for cholesterol crystallization in gallbladder bile. CDLC consists of cholesterol, bilayer-forming amphiphiles, micelle-forming amphiphiles, and water. Phase contrast and differential interference contrast (DIC) microscopy indicate the presence of three microstructure types in all samples studied, and allow for an investigation of the structures' unique geometries. Additionally, confocal microscopy is used for qualitative assessment of surface and internal composition. To complement optical observations, calorimetric (differential-scanning and modulation) experiments, provide the basis for an in-depth understanding of collective and individual thermal behavior. Observed ``transition'' features indicate clustering and ``straightening'' of helical ribbons into short, increasingly thickening, filaments that dissolve with increasing temperature. These results suggest that all microstructures formed in CDLC may coexist in a metastable chemical equilibrium. Further investigation of the CDLC thermal profile should uncover the process of cholesterol crystallization as well as the unique design and function of microstructures formed in this system.

  14. Circumnutation as an autonomous root movement in plants.

    PubMed

    Migliaccio, Fernando; Tassone, Paola; Fortunati, Alessio

    2013-01-01

    Although publications on circumnutation of the aerial parts of flowering plants are numerous and primarily from the time between Darwin (1880) and the 1950s, reports on circumnutation of roots are scarce. With the introduction of modern molecular biology techniques, many topics in the plant sciences have been revitalized; among these is root circumnutation. The most important research in this area has been done on Arabidopsis thaliana, which has roots that behave differently from those of many other plants; roots grown on inclined agar dishes produce a pattern of half waves slanted to one side. When grown instead on horizontally set dishes, the roots grow in loops or in tight right-handed coils that are characterized by a tight torsion to the left-hand. The roots of the few plants that differ from Arabidopsis and have been similarly tested do not present such patterns, because even if they circumnutate generally in a helical pattern, they subsequently straighten. Research on plants in space or on a clinostat has allowed the testing of these roots in a habitat lacking gravity or simulating the lack. Recently, molecular geneticists have started to connect various root behaviors to specific groups of genes. For example, anomalies in auxin responses caused by some genes can be overcome by complementation with wild-type genes. Such important studies contribute to understanding the mechanisms of growth and elongation, processes that are only superficially understood.

  15. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography

    PubMed Central

    Walton, Lucy A.; Bradley, Robert S.; Withers, Philip J.; Newton, Victoria L.; Watson, Rachel E. B.; Austin, Clare; Sherratt, Michael J.

    2015-01-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons. PMID:25975937

  16. Strategies for the AFM-based manipulation of silver nanowires on a flat surface.

    PubMed

    Liu, Hong-Zhi; Wu, Sen; Zhang, Jun-Ming; Bai, Hui-Tian; Jin, Fan; Pang, Hai; Hu, Xiao-Dong

    2017-09-08

    Silver nanowires (Ag NWs) are a promising material for building various sensors and devices at the nanoscale. However, the fast and precise placement of individual Ag NWs is still a challenge today. Atomic force microscopy (AFM) has been widely used to manipulate nanoparticles, yet this technology encounters many difficulties when being applied to the movement of Ag NWs as well as other soft one-dimensional (1D) materials, since the samples are easily distorted or even broken due to friction and adhesion on the substrate. In this paper, two novel manipulation strategies based on the parallel pushing method are presented. This method applies a group of short parallel pushing vectors (PPVs) to the Ag NW along its longitudinal direction. Identical and proportional vectors are respectively proposed to translate and rotate the Ag NWs with a straight-line configuration. The rotation strategy is also applied to straighten flexed Ag NWs. The finite element method simulation is introduced to analyse the behaviour of the Ag NWs as well as to optimize the parameter setting of the PPVs. Experiments are carried out to confirm the efficiency of the presented strategies. By comprehensive application of the new strategies, four Ag NWs are continuously assembled in a rectangular pattern. This study improves the controllability of the position and configuration of Ag NWs on a flat substrate. It also indicates the practicability of automatic nanofabrication using common AFMs.

  17. Local versus global optimal sports techniques in a group of athletes.

    PubMed

    Huchez, Aurore; Haering, Diane; Holvoët, Patrice; Barbier, Franck; Begon, Mickael

    2015-01-01

    Various optimization algorithms have been used to achieve optimal control of sports movements. Nevertheless, no local or global optimization algorithm could be the most effective for solving all optimal control problems. This study aims at comparing local and global optimal solutions in a multistart gradient-based optimization by considering actual repetitive performances of a group of athletes performing a transition move on the uneven bars. Twenty-four trials by eight national-level female gymnasts were recorded using a motion capture system, and then multistart sequential quadratic programming optimizations were performed to obtain global optimal, local optimal and suboptimal solutions. The multistart approach combined with a gradient-based algorithm did not often find the local solution to be the best and proposed several other solutions including global optimal and suboptimal techniques. The qualitative change between actual and optimal techniques provided three directions for training: to increase hip flexion-abduction, to transfer leg and arm angular momentum to the trunk and to straighten hand path to the bar.

  18. Live minimal path for interactive segmentation of medical images

    NASA Astrophysics Data System (ADS)

    Chartrand, Gabriel; Tang, An; Chav, Ramnada; Cresson, Thierry; Chantrel, Steeve; De Guise, Jacques A.

    2015-03-01

    Medical image segmentation is nowadays required for medical device development and in a growing number of clinical and research applications. Since dedicated automatic segmentation methods are not always available, generic and efficient interactive tools can alleviate the burden of manual segmentation. In this paper we propose an interactive segmentation tool based on image warping and minimal path segmentation that is efficient for a wide variety of segmentation tasks. While the user roughly delineates the desired organs boundary, a narrow band along the cursors path is straightened, providing an ideal subspace for feature aligned filtering and minimal path algorithm. Once the segmentation is performed on the narrow band, the path is warped back onto the original image, precisely delineating the desired structure. This tool was found to have a highly intuitive dynamic behavior. It is especially efficient against misleading edges and required only coarse interaction from the user to achieve good precision. The proposed segmentation method was tested for 10 difficult liver segmentations on CT and MRI images, and the resulting 2D overlap Dice coefficient was 99% on average..

  19. Bone grafting, corticotomy, and orthodontics: treatment of cleft alveolus in a chinese cohort.

    PubMed

    Mao, Li-Xia; Shen, Guo-Fang; Fang, Bing; Xia, Yun-Hui; Ma, Xu-Hui; Wang, Bo

    2013-11-01

    Objective : A multimodal therapy was applied to solve a set of related problems including collapse of the posterior segment, high level gingival margin of canine, and resorption of grafted bone in a cohort of Chinese youngsters with cleft lip and palate. This study aimed to evaluate the benefits of this treatment procedure. Methods : Thirty patients with unilateral cleft lip and palate were included in this prospective study. All patients had previously undergone only cleft lip and palate repair and presented with alveolar cleft and an obvious step in the gingival margin between the canine tooth and the teeth beside it. A multimodal therapy that included bone grafting, corticotomy, and orthodontics was applied to solve these problems. Grafted bone volume, parallelism of the roots, root resorption, gingival margin, and mobility of the canine on the cleft side were established before surgery, 1 week after surgery, and after straightening of the canine. Results : Less than 25% of the grafted bone was reabsorbed in 25 of the 30 patients, while less than 50% was resorbed in the remaining five. The roots of the canines on the cleft side were mostly parallel to the adjacent teeth. Root resorption and mobility of the canines were slight. The difference in the gingival margin between the canines on the cleft side and the other side was small. Conclusions : Canines moved into the grafted bone safely and effectively, thus achieving a normal gingival margin and retaining grafted bone volume in one operation.

  20. Non-invasive MRI Assessments of Tissue Microstructures and Macromolecules in the Eye upon Biomechanical or Biochemical Modulation

    PubMed Central

    Ho, Leon C.; Sigal, Ian A.; Jan, Ning-Jiun; Yang, Xiaoling; van der Merwe, Yolandi; Yu, Yu; Chau, Ying; Leung, Christopher K.; Conner, Ian P.; Jin, Tao; Wu, Ed X.; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S.; Chan, Kevin C.

    2016-01-01

    The microstructural organization and composition of the corneoscleral shell (CSS) determine the biomechanical behavior of the eye, and are important in diseases such as glaucoma and myopia. However, limited techniques can assess these properties globally, non-invasively and quantitatively. In this study, we hypothesized that multi-modal magnetic resonance imaging (MRI) can reveal the effects of biomechanical or biochemical modulation on CSS. Upon intraocular pressure (IOP) elevation, CSS appeared hyperintense in both freshly prepared ovine eyes and living rat eyes using T2-weighted MRI. Quantitatively, transverse relaxation time (T2) of CSS increased non-linearly with IOP at 0–40 mmHg and remained longer than unloaded tissues after being unpressurized. IOP loading also increased fractional anisotropy of CSS in diffusion tensor MRI without apparent change in magnetization transfer MRI, suggestive of straightening of microstructural fibers without modification of macromolecular contents. Lastly, treatments with increasing glyceraldehyde (mimicking crosslinking conditions) and chondroitinase-ABC concentrations (mimicking glycosaminoglycan depletion) decreased diffusivities and increased magnetization transfer in cornea, whereas glyceraldehyde also increased magnetization transfer in sclera. In summary, we demonstrated the changing profiles of MRI contrast mechanisms resulting from biomechanical or biochemical modulation of the eye non-invasively. Multi-modal MRI may help evaluate the pathophysiological mechanisms in CSS and the efficacy of corneoscleral treatments. PMID:27561353